This is the famous Checkpoint Charlie (behind the festive tree) that used to be the gateway from East Berlin to the American Sector of West Berlin. It is not the real checkpoint but a recreation as the original was torn down with the wall. The photo is the photo of a young American soldier who served at the checkpoint in the final days of the wall. The building in the background is a museum dedicated to the Berlin Wall and the Cold War. It is a wonderful (if someone disorganized) museum.