This is the airport that I went to for my trip.
Before the trip: Didn't do much research on Berlin really. From the history lessons, I learnt that Berlin was bombarded heavily during the Second World War. Hitler and Nazis were my first words that I thought of. Also Western and Eastern Germany, Red Berlin, communism, Berlin War.....
Didn't have great impressions. Thought that I would be visiting lots of historical buildings, for example the former palace, the former Nazi buildings, the nice Gothic and Greek buildings......
But I was COMPLETELY WRONG!!!!!!
After the trip: Berlin has no 'middle ages buildings'. 85-90% of the buildings were damaged and rebuilt after the world war. The Berlin Wall has fallen down 23 years ago. 95% of Nazi's building were gone. It is a city full of history of the remembrance.
Memorial everywhere in the city. Also, there are so many things happening in Berlin that it's a very lively city. I would say it's a young capital with different cultures and people in the city. I personally think that it's a differentiation of the capitals in Europe which has more modern history than the past middle age ones ;)
Most of the people in Berlin are not originated in Berlin. I learnt a lot of history and how people lived in the West and East Germany during the Cold War and I can clearly see the history was marked everywhere in town.
I highly recommend you to stay there for 4-7 days and explore the city. I personally think that you can explore the city for more than 1 week and each day you will learn some different things :)