Semipalatinsk Test Site is a nuclear test site operated by Soviet Union in Kazakhstan and covers an area of 18,000 km.
The Semipalatinsk Test Site (STS or Semipalatinsk-21), also known as "The Polygon", was the primary testing venue for the Soviet Union's nuclear weapons. It is located on the steppe in northeast Kazakhstan (then the Kazakh SSR), south of the valley of the Irtysh River. 18,000 km (6,950 sq mi) 
Nuclear test site 18,000 km (6,950 sq mi) Soviet Union It is located on the steppe in northeast Kazakhstan (then the Kazakh SSR), south of the valley of the Irtysh River. 
