Semipalatinsk, Kazakhstan

The Semipalatinsk Test Site ("The Polygon") was the primary nuclear testing site for the Soviet Union. It's about 150 kilometres west of the town Semey (named Semipalatinsk until 2007). The place was selected in 1947 by Lavrentiy Beria, head of the Soviet atomic bomb project, who claimed the huge steppe region was totally uninhabited. It wasn't, but nobody cared. Workers from Gulag camps were brought in to build a big complex of buildings and laboratories. Here's what happened.

Now Kazakhstan, formerly Soviet Union

(via Wikimedia Commons 1 - 2)

The first Soviet atomic bomb with its chief designer Yulii Borisovich Khariton

The RDS-1 (codename: First Lightning, but the Americans called it Joe-1, in reference to Stalin) was detonated here on 29 August 1949 – without evacuating the nearby cities and villages. The Soviet Union became the second nation to successfully develop a nuclear bomb, but this project made a terrible impact on the local people.

(via )

The Joe-4, the first thermonuclear weapon test in USSR, exploded on August 12, 1953

It detonated with a force equivalent to 400 kilotons of TNT. (1, 700 TJ) It was the "layer cake" (Sloika) model: fission and fusion fuel (lithium-6 deutheride) were "layered" here, similar to the never-tested Edward Teller design.

456 tests in four decades

Between 1949 and 1989 this place saw 456 nuclear tests, including 340 underground and 116 atmospheric explosions with mushroom clouds. These were roughly the equivalent of 2500 Hiroshima atomic bombs. The Soviets conducted these tests without any regard for the effects on the local environment or the almost quarter-million inhabitants of the area.

On the picture: Russian Atomic Weapon Museum, with the Joe-4, Joe-2 and Joe-1, (left to right)

The early bombs were "dirty", so there is a really huge amount of plutonium on the fields

The big, aircraft wing-like things named "geese" and other buildings without window glass were built to measure the shockwaves of explosions.