This page is divided into to sections. The first section contains general information about Denmark and the secound part contains information about all the cities I have been to.
General information about Germany
Germany is the largest country in Central Europe. It is bordered to the north by Denmark, to the east by Poland and the Czech Republic, to the south by Austria and Switzerland, and to the west by France, Luxembourg,Belgium and the Netherlands. Germany is a federation of 16 states, roughly corresponding to regions with their own distinct and unique cultures.
The roots of German history and culture date back to the Germanic tribes and after that to the Holy Roman Empire. Since the early middle ages Germany started to split into hundreds of small states. It was the Napoleonic wars that started the process of unification, which ended in 1871, when a large number of previously independent German kingdoms united under Prussian leadership to form the German Empire. The empire ended in 1918 when Emperor Wilhelm II was forced to abdicate the throne at the time of Germany's defeat at the end of World War I (1914-1918) and was followed by the short-lived and ill fated so called Weimar Republic, which tried in vain to completely establish a liberal and democratic regime. Because the young republic was plagued with massive economic problems stemming from the war and disgrace for a humiliating defeat in World War I, strong anti-democratic forces took advantage of the inherent organizational problems of the Weimar Constitution and the Nazis were able to seize power in 1933.
After the devastating defeat in World War II (1939-1945), Germany was divided into four sectors, controlled by the French, British, US and Soviet forces. United Kingdom and the US decided to merge their sectors, followed by the French. Silesia, Pomerania and the southern part of East Prussia came under Polish administration according to the international agreement of the allies. With the beginning of the Cold War, the remaining central and western parts of the country were divided into an eastern part under Soviet control, and a western part which was controlled directly by the Western Allies. The western part was transformed into the Federal Republic of Germany (FRG), a democratic nation with Bonn as the provisional capital city, while the Soviet-controlled zone became the communist/authoritarian Soviet style German Democratic Republic (GDR). Berlin had a special status as it was divided among the Soviets and the West, with the eastern part featuring as the capital of the GDR.
Germany was reunited peacefully in 1990, a year after the fall and collapse of the GDR's Communist regime and the opening of the iron curtain that separated German families by the barrel of a gun for decades. The re-established eastern states joined the Federal Republic of Germany on the 3rd of October 1990, a day which is since celebrated as the national holiday, German Unification Day.
The official language of Germany is German. The standard register of German is called "Hochdeutsch" (High German), which can be understood by all mother-tongue speakers of German and spoken by almost all when necessary. However, every region has its own dialect, which might pose a challenge sometimes to those who speak even good German and even to native speakers as well. This is usually noticeable only in the south (not too much in big cities such as Stuttgart or Munich though) and rural areas of the north and east. Thus, when travelling in Bavaria, Saxony and Baden, you are stepping foot in places where dialect remains a strong part of the local identity. The general rule is that south of the Main River divides north Germany from the south in both language and local culture.
If you intend address the person you're speaking to in German, refer to the person as "Sie" if you aren't acquainted with that person yet. "Du" can be used if both of you are already close (the form of the verbs will also change).
All Germans learn English at school, so you should be able to get by with English in most places especially in the former West Germany. Many people--especially in the tourism industry and higher educated persons--also speak French, Russian or Spanish, but if you can't speak German, English remains your best bet.
Travel to Germany
Flying can be the cheapest way to get to Germany and from there to other European countries, especially if the flights are booked well in advance. The most important international and domestic airports in Germany are Frankfurt, Munich and Düsseldorf, Berlin-Tegel, Cologne, Hamburg and Stuttgart.
Frankfurt is Germany's main hub - one of Europe's four major hubs - and the destination of most intercontinental flights but Munich is a growing secondary hub. Travellers can easily fly in from most places of the world and then connect with Germany's biggest and most respected airline Lufthansa, which is a member of the Star Alliance.
The airports of Frankfurt, Düsseldorf and Köln/Bonn are connected to the InterCityExpress high speed rail lines. The others all feature either a commuter rail station or some sort of connection to the nearest rail station as well as public transport to the central station of the respective cities. Lufthansa's passengers travelling from Frankfurt Airport have the option to check-in their luggage in Cologne, Düsseldorf or Stuttgart train stations and connect to the airport by ICE (AIRrailservice). If doing so, be sure to book the train journey like a Lufthansa connecting flight (ie in advance together with the flight), otherwise you will be responsible for a missed connection.
Regular train services connect Germany with all neighbouring countries - most operated by Deutsche Bahn (DB). Almost all neighbouring countries and even some non-neighbouring countries are quite well connected with "EuroCity" (EC} trains. They are a little bit slower and slightly less comfortable than the European high speed trains but nevertheless reach up to 200 km/h. They are a worthwhile way to travel - not only for budget travellers or landscape viewers.There are also several European high speed trains to cross into or get out of Germany.
International ferry services exist, notably to Scandinavia. Depending on the country your are leaving from towards Germany, different companies offer tickets. Eurolines, a cooperation of European bus companies, sells tickets to and from almost any other European country. The German partner is called Touring.
German is of course the main language in Berlin but you can easily find information in English and sometimes in French. Due to the football World Cup in 2006 all public transportation staff got language training and should be able to help you in English (although probably with a strong German accent). If you seem to be lost or hesitating in a public transport station a member of staff could come to your assistance but don't count on that. You can easily approach a group of (preferably young) bystanders and ask for advice in English.
Travelling within Germany
German transportation runs with German efficiency, and getting around the country is a snap - although you'll need to pay top price for top speed. The most popular options by far are to rent a car, or take the train. If the train is too expensive for you, travelling by arranged ride-sharing is often a viable alternative in Germany. Domestic flights are mainly used for business, with the train being a simpler and often (but not always) cheaper alternative for other travel.
Germany offers a fast and, if booked in advance, affordable railway system that reaches most parts of the country. Unless you travel by car, rail is likely to be your major mode of transport. Crossing Germany from Munich in the south to Hamburg in the north will usually take around 6 hours, while driving by car will take around 8 hours.
All major cities are linked by DB's InterCity Express (ICE) and regular InterCity trains. ICE is a system of high speed trains going up to 300 km/h within Germany (the top speed of 320 km/h is only reached in France, when going to and from Paris). Top speeds are only reached on newly built or upgraded parts of the network; on "old" tracks the ICE will only go as fast as regular IC trains. On most main lines you will arrive significantly faster than by car.
Germany has a world-famous network of excellent roads and Autobahnen (motorways) with no toll or fees for cars (trucks have to pay), but gasoline prices are kept high by taxation. Ride-sharing (or pre-arranged hitchiking - MFZ) is popular in Germany and the fare for a ride is often much cheaper than the railway fare.
Places to sleep
There are many types of tourist accommodation, ranging from hotels, pensions and villas, to camping and even monasteries. You may use i.e. hotels.com, booking.com or hostelworld.com to find somewhere to sleep. If you want to rent a private home Airbnb.com is somewhere you could check out.
The power supply runs at 230V/50Hz. Almost all outlets use the Schuko plug, most appliances have a thinner but compatible Europlug. Adapters for other plugs are widely available in electronics stores.
Money and banking
Germany is part of the European Union and the Eurozone. Euro replaced Deutsche Mark in 2002. If you want to exchange money, you can do so at any bank where you can also cash in your traveller's cheques. Currency exchanges, once a common sight, have all but disappeared since the introduction of the Euro. Credit cards are well accepted in Germany. Most ATMs will allow you to withdraw money with your credit card, but you'll need to know your card's PIN for that.
Vaccine and health
If you have an non-urgent medical problem, you may choose from any local doctor. The German health system allows specialists to run their own surgery so you usually will be able to find every discipline from Dentistry to Neurology on duty within reasonable reach. In remote regions finding a doctor might require a ride to the next town but the German infrastructure allows fast connections. GPs/family doctors will usually describe themselves as "Allgemeinmediziner" - meaning "general practitioner".
Pharmacies are called "Apotheke" and are marked by a big, red "A" symbol. At least one pharmacy in the area will be open at all times (usually a different one every day), and all pharmacies will post the name and address of the pharmacy-on-duty in the window. Some medication that is sometimes freely available in other countries (e.g. antibiotics and the "morning-after pill") needs a prescription in Germany, so you may want to check before your journey. The staff of an Apotheke have specially trained personnel, as it is mandatory to have a university degree in pharmaceutics to run an Apotheke in Germany. A German pharmacist and his staff is not only able to offer advice on medications, but also obliged to do so. Thus, expect them to ask which person the medication will be intended for, and to give some mostly helpful advise on it. In Germany, it is not considered shameful to talk about disease, thus, the dialogue might be quite straightforward. Waiting other customers will usually wait behind a line painted on the floor as a measure to increase discretion.
In Germany pharmaceuticals tend to be expensive, so it might be wise to ask the pharmacist for "Generika" (generic drugs): A "Generikum" is virtually the same produce, often even produced by the same pharmaceutical trust, just lacking the well-known brand name and being considerably cheaper.
EU citizens that are members of any public health insurance can get a European Health Insurance Card. The card is issued by your insurance provider and lets you use the public health care system in any EU country, including Germany. If you are an EU citizen, you simply have to tell a doctor or the hospital that it goes through the 'AOK', the German state health insurance scheme. If doctors and hospitals don't accept this, go to the local AOK office and they will usually telephone them to confirm.
If you're from outside the EU, or if you have a private health insurance, check if your insurance is valid in Germany. If not, get a travel health insurance for the trip - German health care is expensive.
Foreign insurance, even if it covers travel abroad, may not be accepted by local hospitals, i.e. you may have to pay up front and claim it back from the insurance company. (Be sure to keep the originals safe.) Alternatively, you might be sent a bill in the post.
You should be aware of rabies (Tollwut) which has been a problem in some areas in the past, even if forestry officials combat it very seriously. If you want to go to Germany for hiking or camping you should inform yourself about the situation at your destination and take appropriate precautions. Normally, you won't have to worry about it because the main transmitting animal is the fox.
The biggest risks hikers and camper face are two diseases transmitted by ticks. In some parts of Germany there is a (low) risk of contracting tick-borne encephalitis; vaccination is advised if you plan out-door activities in high-risk areas. The risk of Lyme disease is higher and vaccination is not available. Therefore you should try to prevent tick-bites by wearing long trousers and appropriate shoes. Chemical repellents can also be effective. You should also check for ticks afterwards since the risk of transmission is lower if the tick is removed early. The safest way to remove a tick is by using a credit card sized device called a "Zeckenkarte" (tick card), wich you can get at most pharmacies. Other methods (fingers, using glue, etc.) might lead to the tick injecting even more infectious material into the wound. If in any doubt consult a doctor.
There are no border controls between countries that have signed and implemented this treaty - the European Union (except some few countries). Likewise, a visa granted for any Schengen member is valid in all other countries that have signed and implemented the treaty. But be careful: not all EU members have signed the Schengen treaty, and not all Schengen members are part of the European Union. This means that there may be spot customs checks but no immigration checks (travelling within Schengen but to/from a non-EU country) or you may have to clear immigration but not customs (travelling within the EU but to/from a non-Schengen country).
Germany is a very safe country. Crimes rates are low and the rule of law is strictly enforced. Violent crimes (homicide, robberies, rape, assault) are very rare compared to most African and American countries. For instance, 2010 homicide rates were, with 0.86 cases per 100,000 inhabitants, significantly lower than in the UK (1.17), Australia (1.20), France (1.31), Canada (1.81) and the US (5.0) - and they continue to decline. Pickpockets may sometimes be an issue in large cities or at events with large crowds. Begging is not uncommon in some larger cities, but not to a greater extent than in most other major cities, and you will rarely experience aggressive beggars. Some beggars are organized in groups. Be aware that flashing any cardboard sign very near to your body could be a pickpocket trick.
If you stay in Berlin or Hamburg (Schanzenviertel) around the first of May, Tag der Arbeit, expect demonstrations that frequently evolve into clashes between the police and a minority of the demonstrators.
Take the usual precautions (such as not walking in parks alone in the early hours, not leaving your camera unattended or bicycle unlocked, and not flashing around a big fat wallet) and you will most likely not encounter any crime at all while staying in Germany.
Prostitution (including brothels and non-exploitative pimping) is a legal business in Germany and is a common sight (especially in cities like Berlin and Hamburg).
German Police officers (Polizei) are trained to be always helpful, not corrupt, professional and trustworthy, but tend to be rather strict in enforcing the law, which means that one should not expect that exceptions are made for tourists. When dealing with police remain calm and courteous and you will be treated calm and curteous. Avoid getting into any confrontation since you may be fined for insulting or even physically resisting police officers. Most police officers should speak/understand at least basic English or at least have colleagues who do so. The younger they are, the better the chance to catch one who speaks good English.
The police can ask you for identification anytime. However if you refuse to identify yourself, the police can only enforce this if they have a reason to suspect you are a danger for public safety or public order, that you committed a crime or are in an area where crimes are typically comitted, at the border, within 30 km from the border, at airports, railway stations, in public transportation and in some more circumstances. As this is a long list of reasons to enforce identification, police can easily find (or invent) one that applies on you.
If you are a victim of crime (for example robbery, assault or theft in public) and wave down an oncoming patrol car or officer, it is not uncommon that the officers will (sometimes rather abruptly: "Einsteigen") command you to enter the back seat of the police vehicle. This is an action to start an instant manhunt to identify and arrest the suspect. In this case remember that you are not under arrest but there to help the officers enforce the law and, hopefully, recover your property. In general, if police ask you to enter some police car, to attend them, or to follow them to some station, and you have not committed any offence, you are not under arrest. This even applies if they body search you before entering the police car, because, in some states, police are simply ordered to routine search any person who enters a police car.
German cuisine and drink
Tap water has a good quality, is very strictly controlled and can be freely used for consumption. Exceptions have to be labelled ("Kein Trinkwasser" = not drinking water), usually found on fountains and in trains.
Low strength alcohol like beer and wine may be bought and consumed if you're 16 years and older. However, spirits and drinks mixed with those (including the popular 'Alcopops') are available only at 18. It's not technically illegal for younger people to drink, but it is illegal to allow them to drink on premises. Parents can allow their children to drink alcohol within the limits of good parenting and child's welfare.
Being a federal republic, Germany is very much a decentralised country, which embraces the cultural differences between the regions. Some travellers will perhaps only think of beer, Lederhosen and Oktoberfest when Germany comes to mind, but Germany's famous alpine and beer culture is mostly centered around Bavaria and Munich. Here the beer is traditionally served in 1 litre mugs (normally not in pubs and restaurants, though). The annual Oktoberfest is Europe's most visited festival and the world's largest fair. Germany's south-western regions, however, are well known for their wine growing areas (e.g. Rheinhessen and Palatinate) and Bad Dürkheim on the 'German Wine Route' (Deutsche Weinstraße) organises the biggest wine festival worldwide with over 600,000 visitors annually.
German food usually sticks to its roots and a typical dish will consist of meat with some form of potatoes and gravy, accompanied by vegetables or salad. Modern German cuisine has been influenced by other European countries such as Italy and France to become lighter. Dishes show a great local diversity which is interesting to discover.
Since most bigger employers have a canteen for their employees, you will find relatively few sandwich shops and takeaways, and eating-out culture in Germany is dominated by the Gasthaus/Gasthof and restaurants. Starting from the north of Germany going south you will find a tremendous variety of food and each region sticks to it origins. The coastal regions are fond of seafood and famous dishes include “Finkenwerder Scholle”, going south to the region of Cologne you will find Sauerbraten (a roast marinated in vinegar), if made really traditionally it's from horse meat.
Germans are very fond of their bread, which they make in many variations. This is the food that Germans tend to miss most when away from home. Most people like their bread relatively dark and dense and scorn the soft loaves sold in other countries. Bakeries will rarely provide less than twenty different sorts of bread and it's worth trying a few of them.
For centuries, beer-making in Bavaria has been governed by the Reinheitsgebot (purity law) that was made national policy with the unification of Germany in 1871, which states that German beer may be made only from hops, malt, yeast and water. The Reinheitsgebot has come down with the European integration, but German breweries still have to stick to it since for them, national law applies.
The domestic beer market is not dominated by one or a only a few big breweries. Even though there are some big players, the regional diversity is enormous, and there are over 1200 breweries with most of them serving only local markets. Usually bars and restaurants serve the local varieties that differ from town to town. When sitting in a German Kneipe, a local beer is always an option, and often the only option.
Undisputed capital of "Apfelwein" cider in Germany is Frankfurt. Locals love their cider and it is very popular around there. There are even special bars ("Apfelweinkneipe") that will serve only "Apfelwein" and some gastronomic specialities. Cider is often served in a special jug called "Bembel". The taste is slightly different from Ciders in other countries and tends to be quite refreshing.
Germans are just as passionate about their wines as they are about their beer. The similarities don't stop here, both products are often produced by small companies if not by families or individuals, and the best wines are consumed locally and only the remaining ones are exported. The production of wine has a 2000 year old history in Germany as learned from the Rheinisches Landesmuseum Trier, but of course this was a roman settlement at this time. Sunshine is the limiting factor for the production of wines in Germany and therefore the wine production is limited to the south. White wine plays a main role in the wine production, but some areas produce red wines (Ahr, Baden Württemberg). White wines are produced from Riesling, Kerner and Müller-Thurgau grapes (there are a lot more, but to name them all would be too much), and produce generally fresh and fruity wines. German wines can be rich in acid and are quite refreshing. It is generally accepted that Riesling grapes produce the best German wines, but they demand a lot of sunshine and they grow best in very exposed areas such the Mosel, Rheingau, Bergstrasse, Kaiserstuhl and Pfalz.
The best way to learn about wines is go to the place where they are grown and taste them on the spot. This is called "Weinprobe" and is generally free of charge though in touristic areas you have to pay a small fee. Good wines usually go together with good food and therefore it is well worth it to visit some of those places.
Another nice opportunity to get a taste of local wine is the so-called Straußenwirtschaft, Besenwirtschaft or Heckenwirtschaft. These are little "pubs" or gardens where a wine-producer sells his own wine, normally with little meals such as sandwiches or cheese and ham. Normally, they are open only in summer and autumn, and not longer than 4 months a year (due to legal regulations). As they are sometimes located in the vineyards or in some backstreets, they are not always easy to find, so you best ask a local for the next (or best) Straußenwirtschaft he knows.
During the fall you can buy "Federweisser" in south-western Germany. This is a partially fermented white wine and contains some alcohol (depending on age), but tastes very sweet. It is also available from red grapes, being called "Roter Sauser".
I have made many travel maps for German cities in Googl MyMaps and you can see them ny opening this link.
Cities I have been to in Germany
Berlin is the capital city of Germany and one of the 16 states (Länder) of the Federal Republic of Germany. Berlin is the largest city in Germany and has a population of 4.5 million within its metropolitan area and 3.5 million from over 190 countries within the city limits.
Berlin is best known for its historical associations as the German capital, internationalism and tolerance, lively nightlife, its many cafés, clubs, bars, street art, and numerous museums, palaces, and other sites of historic interest. Berlin's architecture is quite varied. Although badly damaged in the final years of World War II and broken apart during the Cold War, Berlin has reconstructed itself greatly, especially with the reunification push after the fall of the Berlin Wall in 1989.
It is now possible to see representatives of many different historic periods in a short time within the city centre, from a few surviving medieval buildings near Alexanderplatz, to the ultra modern glass and steel structures at Potsdamer Platz. Because of its tumultuous history, Berlin remains a city with many distinctive neighbourhoods. Brandenburger Tor is a symbol of division during the world war, which now shows German reunification. It was built after the Acropolis in Athens and was completed in 1799 as the royal city-gate.
Germany was later on divided into east and west, In August 13,1961, East Germans permanently closed the border between East and West. The wall had 45,000 sections of reinforced concrete and included 79 miles of fencing, nearly 300 watchtowers and 250 guard dogs. Still more than 5,000 people escaped to freedom.
The foundation of Berlin was very multicultural. The surrounding area was populated by Germanic Swabian and Burgundian tribes, as well as Slavic Wends in pre-Christian times, and the Wends have stuck around. Their modern descendants are the Sorbian Slavic-language minority who live in villages southeast of Berlin near the Spree River.
In the beginning of the 13th century, two towns (Berlin and Cölln) developed on each side of the river Spree (today the Nikolaiviertel and the quarter next to it beyond the river). As the population grew, the towns merged and Berlin became a centre for commerce and agriculture. This area stayed small (about 10,000 inhabitants) up to the late 17th century, because of the 30 years' war in the beginning of the 17th century, which led to death of about half of the population.
Since the late 17th century, when large numbers of French Huguenots fled religious persecution, Berlin has welcomed religious, economic and other asylum seekers. In 1701 Berlin became the capital of Prussia and in 1710 Berlin and surrounding former autonomous cities were merged to a bigger Berlin.
In 1871 Berlin became the capital of the new founded German Reich and a few years later, it became a city with more than one million inhabitants because of the immensely growing industry.
Shortly after the first World War, in 1920, the last of the annexations of surrounding cities of Berlin led to the foundation of the Berlin as we know it now. After the coming into power of the National Socialists ("Nazis"), Berlin became the capital of the so called Third Reich and the domicile and office of Hitler (although the triumph of Hitler and his henchmen started in the south of Germany).
WW II led to destruction of most of central Berlin, thus many of the buildings which we see nowadays are reconstructed or planned and built after the war, which led to a very fragmented cityscape in most parts of the inner town. Berlin was divided into four sectors (West Berlin into the French, American and British sector, East Berlin belonged to the USSR). In 1949 the German Democratic Republic ("East Germany") was founded with East Berlin as its capital. West Berlin remained occupied by the western Allies and kept a close relationship with West Germany (with Bonn as the capital) and was an exclave (political island) in East Germany. Because of the growing tensions between West Germany and the GDR, the GDR built a militarized and increasingly impassable border between the states, and then in 1961 surrounded West Berlin with a wall.
In late 1989 East German citizens began to peacefully demonstrate in increasing numbers; this led to the fall of the Berlin Wall. In 1990 West Germany and East Germany were united. Berlin became once again the capital of Germany.
After WW2 and the building of the wall, large numbers of immigrants from Turkey were invited to West Berlin to work in the growing industry sector; in East Berlin the jobs were done mostly by Vietnamese immigrants. But also people from other communist countries, including the former Yugoslavia, not to mention Soviet soldiers who refused to return home, have helped to make Berlin more multicultural than ever.
Berlin is also a youth-oriented city. Before German unification, West Berliners were exempt from the West German civil/military service requirement. Social activists, pacifists and anarchists of all moved to Berlin for that reason alone. Musicians and artists were given state subsidies. It was easy to stay out all night thanks to liberal bar licensing laws, and staying at university for years without ever getting a degree was a great way to kill time. In contrast with most of Germany, Prenzlauer Berg is said to have the highest per-capita birth rate in Europe (in fact it just seems so because of the high percentage of young women in the district).
After the fall of the wall, Berlin - especially the former East - has evolved into a cultural hub. Artists and other creative souls flocked to the city in swarms after reunification, primarily due to the extremely low cost of living in the East. Despite the increased prices and gentrification as a result, Berlin has become a centre for art, design, multimedia, electronic music, and fashion among other things. The particularly high number of students and young people in the city has only helped this cause. Just stroll down a street in Prenzlauer Berg, Friedrichshain, or Mitte to get a glimpse of the new East Berlin.
Berlin is a relatively young city by European standards, dating to the thirteenth century, and it has always had a reputation as a place filled with people from elsewhere. It may seem tough to find someone born and raised here! This is part of Berlin's charm: it never gets stuck in a rut.
Berlin is a huge city. You can make use of the excellent bus, tram, train and underground services to get around. Taxi services are also easy to use and a bit less expensive than in many other big Central European cities. You can hail a cab (the yellow light on the top shows the cab is available), or find a taxi rank (Taxistand). Taxi drivers are in general able to speak English. If you ask for a short trip (Kurzstrecke), as long as it's under 2km and before the taxi driver starts the meter running, the trip normally is cheaper, €4. This only applies if you flag the taxi down on the street, not if you get in at a taxi rank. Also, some online services like Talixo facilitate online and in-app booking.
Check the Berlin route planner (in English) to get excellent maps and schedules for the U-Bahn, buses, S-Bahn and trams, or to print your personal journey planner. The route planer can also calculate the fastest door-to-door connection for you destination for any given day and hour. The Berliner Verkehrsbetriebe (BVG) have a detailed fare list on their web site.
If you like walking tours Sandemans New Europe have several walking tours in Berlin.
Berlin has a vast array of museums. Most museums charge admission for people 18 years of age or older - usually €6 to €10 for the big museums. Discounts (usually 50%) are available for students and disabled people with identification. Children under 18 years free. A nice offer for museum addicts is the three day pass Museum Pass for €24 which grants entrance to all the normal exhibitions of the approximately 55 state-run museums and public foundations. Most museums are closed on Mondays; notable exceptions include the Neues Museum and the Deutsches Historisches Museum, which are open daily. Museumsportal Berlin, a collective web initiative, offers easy access to information on all museums, memorials, castles and collections and on current and upcoming exhibitions.
I haven't been there, at least yet, but Berliner Unterwelten. Berlin's surface is just the visible part of the city: among the large squares and streets, relics, tunnels and secret passages from Berlin's changing history slumber. Particularly impressive are the ruins of bunkers. Since 1997, the Berlin non-profit Underworlds Association has managed these fateful buildings. 1999 is the first time that visitors are taken on guided tours through the extensive bunker complex in Gesundbrunnen U-Bahnhof. The Association is formed to explore, document and preserve Berlin's underground infrastructure and make it available to the public.
As Berlin is a city of art, it is quite easy to find an art gallery on your way. They provide a nice opportunity to have a look at modern artists' work in a not-so-crowded environment for free.
Checkpoint Charlie is one of the most famous crossing points through the wall that divided east and west back in the days and it is still standing. Right next to it is Mauermuseum which tells about the daily life in Berlin during the cold war.