In July 1954, Novaya Zemlya was designated the Novaya Zemlya Test Site. It was used as a test site throughout the cold war. In 1961 Tsar Bomba was dropped on the archipelago. The Tsar Bomb was the largest nuclear bomb ever made at 50 Mt. By contrast, the largest weapon ever produced by the United States, the now-decommissioned B41, had a predicted maximum yield of 25 Mt.