Nowadays, the Friedrichstrasse is one of Berlins most famous shopping-streets. Flagshipstores all over the place, always crowded - mostly with tourists. Walk south and you'll find a great historical spot: "Checkpoint Charlie", the best-known Berlin Wall crossing point between East Berlin and West Berlin during the Cold War.
For the Berlin-series I just used an old 50mm lens, with manual focus only. Topic is street / documentation.