Bunker Wollenberg, Cold War military bunker in Bad Freienwalde, Germany.

Bunker Wollenberg is an underground military facility in Bad Freienwalde that served as a communication center for former East Germany. The multi-story structure with its thick concrete walls was built to ensure operations could continue under extreme conditions.

Built in the mid-1980s as Tropospheric Radio Centre 301, the bunker was one of three identical East German stations in the Warsaw Pact's BARS network, alongside Langsdorf and Röhrsdorf. It was disguised as a military flight weather station and codenamed "TUSHURKA". In May 1990 the first reserve government channels were routed abroad through it. Today the association Militärhistorisches Sonderobjekt 301 Wollenberg e. V. runs it as a museum.

The bunker served as a key communication hub for the National People's Army and shows today how soldiers worked during the Cold War. The exhibition displays personal items and equipment that document the daily operations of this hidden facility.

Visits happen through guided tours that require advance booking and provide access to the rooms and communication systems. Visitors should expect stairs and narrow corridors since it is an underground military structure.

The bunker preserves a rare Soviet radio communication system R-417 that survived in this form almost nowhere else. This specialized equipment shows the technological dependence of East Germany on Soviet military technology during the Cold War.