A secret Soviet nuclear weapons bunker located in northeastern Poland, near the town of Węgrów in the Podlaskie Voivodeship. This clandestine site, built in the 1960s during the Cold War, was one of several such facilities constructed by the Soviet Union in Poland. The bunker was carefully concealed to be invisible from the air and did not appear on maps, hiding its lethal secret from the Polish people.
It housed nuclear warheads, part of the Soviet Union's strategic arsenal in the region during the tense decades of the Cold War. The bunker's existence and purpose were only revealed after the fall of the Soviet Union.