Former GDR Border Watchtower at Jungfernsee

At the narrowest point of the Jungfernsee, a pontoon barrier was set up as a border. There was also a landing stage for a squadron of boats used by East German border troops.

The traces of the German-German division have almost completely disappeared in Potsdam. Now eight steles between Villa Schöningen and Villa Gutmann on the bank of the Jungfernsee commemorate the restricted area of the GDR state border with West Berlin. Here you can find the information path "Attention border - the restricted area of the GDR in Potsdam 1961-1989".The post tower was built in 1976. From there, the cable winch was released, with which the Bertini Narrows could be blocked for shipping. At that time, a barrier made of pontoons was moored across the lake with strong cables, which allowed narrow passages on both banks. When the crew of the post tower pressed the button, a steel net shot up in the water, rattling and foaming.In 1964, a border crossing for transit shipping was set up on the Bertini-Enge, which supplied West Berlin with fuel and freight via the Elbe and Havel.Today only the listed post tower reminds of this, a diesel hall built for power supply right next to it, three light masts at the former landing stage and the canal in the ground, in which the steel cable rested, with which the net in the lake was lowered and raised.Source: maz-online.de/Lokales/Potsdam/Berliner-Mauer-taucht-in-Potsdam-aus-der-Versenken-auf

One must not forget that the GDR liked to call itself a "peace state".