It was at this Balapan site during the cold war that the Soviets compared the effect of a nuclear attack on a American Atlas missile silo against one of their own intercontinental ballistic missile silos. They recreated a supposedly secret Atlas silo and placed it near one of their own SSB installations. Then they set off a nuclear bomb to see the effects the blast would have on the two structures.
We don't know the results of that experiment as the Soviets returned to Kazakhstan in 1995 to obliterate this site by conventional means, preventing anyone from gathering data. The remains of the Atlas silo door and hardware are pictured below.