Degelen

Around hundred horizontal tunnels were bored into the mountain to carry out nuclear tests operated by the USSR armed forces.

The abandoned electrical installations and the rails that had been used to transport the nuclear devices deep into the earth became a target of scavengers.

Some of the tunnels were stocked with undetonated plutonium and they had to be sealed more thoroughly as part of a plan to eliminate nuclear weapons testing infrastructure in the mountain range.

A deep valley that opens to the east runs across the middle of the range dividing it into two segments: Ulken Degelen, the northern one, stretches from northwest to the southeast for 15 kilometers (9.3 mi).

In order to assess recovery, experimental zones have been planted with poplar, silver birch, Tatar maple and elm seedlings.

Location of Degelen within the Semipalatinsk Polygon .