Reichstag (German Parliament seat) is in fact the oldest building in this area. All other surrounding dwellings are contemporary and amazing. I loved the concept of marrying old and new and bringing life to it. What helps is the promenade along river, green space in front of it and also the dome that allows overlooking the rest of the city. After you have queued for a bit of time. But the view is certainly worth waiting! I would suggest going there about up to 1 h before sunset (they remain open until 23h).