One of the most beautiful pieces of Berlin actually is a piece of another city (Al-Hillah, Iraq). Normally Berliners are laid back and like to hang around, drink beer and chat till sunrise. Sometimes they do get excited though, and then they start taking old war-battered stones and piecing them together to (re)form walls. The results are great as can be seen all over Berlin, but the Ishtar gate in the Pergamon museum is where they’ve really outdone themselves.
Wim Wenders shot Wings of Desire here. It's a quiet place to work and definitely a gorgeous place to visit. Combine it with a visit to the Philharmonic, just across the street. Affiliation is 30 euros per year and you have lots of desks all over the library to choose from.
The Zoo and the Aquarium is on the things that never changed during the years. Everytime I visit it looks exactly the way when I first went when I was a little child. This place gives me a lot of inspiration, I like the way they want to make the cage enviroment look natural with artificiel light.
Tuesday's lunch hour tip is the amazing Berlin Philarmonic. A short-duration concert (around an hour) happens every Tuesday at 13h, for free. People make the Philarmonie's foyer full, sitting on the stairs, on the ground and everywhere around. Little advice: bring with you a little cushion for more comfort and try to arrive early to find the good spots.