One of the many sights was a remaining section of the Berlin Wall.
I also visited the most famous symbol of Berlin (The Brandenburg Gate)
The tour was over 4 hours long and quite informative. I almost felt like I was learning something.
Checkpoint Charlie was also on the tour and it was crucial in history and almost served as the starting point of WWIII
Later I visited the university that has sculpted such minds as Nietzsche and Einstein.