The Polygon in the former Soviet closed city Semipalatinsk (known today as Semey) was the primary nuclear test site of the Soviet Union. In total, 456 nuclear tests were conducted here between 1949 and 1989, including 340 underground and 116 atmospheric explosions. Altogether, the number of nuclear explosions at Semipalatinsk equals more than 2,500 Hiroshima bombs. A huge number of craters, partly filled with water, testify to these experiments.
Located relatively close to a major settlements, this is also the site of one of the most horrible legacies of the Cold War era: where the Soviet Union tested nuclear bombs on civilians. The military conducted these nuclear tests without regard to the health effects on the 200,000 residents of the Semipalatinsk area, who weren't evacuated or warned during the actual explosions. Residents noticed health terrible problems soon after the first tests, and though the site was finally closed in 1989, the legacy of the nuclear tests lingers on. An area of more than 18,000 square kilometers is heavily contaminated and over a million people have been diagnosed with health problems. Nevertheless, even today people continue to live in the Polygon area.