If your are coming from a smaller place like Hamburg you will notice how large this city is. You need a bike or a train to get from one end to another and this takes some time. Some districts feel like a small city you could explore for hours. And because of it´s history Berlin is way different from other cities. Berlin was divided into two pieces in the past. So both sides had a different look and feel.
There is the wall built by the Russians after the second world war. You should take some time to visit the wall memorial so see the watch tower and some parts of the original wall. You learn more about people who tried to escape from east Berlin by digging tunnels or climbing on the rooftop of houses near the wall. This will give you a good picture of what happened to this city in terms of freedom and how people lived with it.
But Berlin is also a green and quiet city. Most people see Berlin as a loud and trendy city. But there are many places like parks, churches and backyards that are quiet and nearly free from other people. This is what makes Berlin so great for me. This place is loud and quiet at the same time. There are many great historic places full magic.
And don´t forget. Berlin is also the capital city of Hipsterism and any other form of extravagant lifestyle. Many people try to get everybody's attention. Sometimes it looks great. But some styles are making me laughing. But taste is different. And that is a good thing...
If you visit districts like Prenzlauer Berg or Kreuzberg you will find dozens of stylish people looking on illuminated displays and working on something important. But don´t think it´s a fad or overrated. Those people open up stores and invest money and time into new (and odd) things. Sometimes it feels a bit over the top but the hipster culture lasts now for more than ten years and is can´t be reduced to one word.
And like no other city you will find art everywhere in Berlin. Because the wall was like a great canvas to all the street-artists back in the eighties to show their protest. This was (and is) a magnet for artists around the world. You can see the results in nearly every corner of Berlin.
And there is also the classic tourist part of Berlin. The Brandenburger Tor, Checkpoint Charlie or the Reichstag building are waiting for new visitors every day. They polished every stone at this places, so they look like freshly build. Beware of the tourist traps. They sell a lot of crap at this places.
Berlin has so many different faces and places. It is always worth a visit...