Between 1966 and 1972, over 200 round watchtowers type BT 6 were built along the Berlin Wall to replace older wooden towers. The very last remaining Rundblickbeobachtungsturm ('view-watching-tower') has been restored and is open for visitors. Climb up the steep ladder to see the cabin where the poor border guards had to spend their 8-hour shifts. The heavy metal shutters were for protection, in case the enemy in the West opened fire. Find it in the dead-end street off Stresemannstrasse, opposite the western exit of U-Bahn station Potsdamer Platz.