The place we are going to speak about in this post is really hard to visit. It's surrounded by a fence and guarded by special men with dogs. This is the highly protected Command Post of the Missile Division. Its building wasn't finished - the military abandoned it in 2010. And now it's being actively sawed up into pieces of metal...
Having lost its top, the "sphere" (also known as a "hedgehog") became a bit less attractive though its inner structure is now much better seen.
The sphere was designed to enable survival during a nuclear war.
A hollow metal ball was built inside a large mine. Then a huge 4-story module block was suspended on huge shock absorbers inside of it. It contained control and communications equipment, life support systems and rest rooms.
The top of the ball was closed by a semicircular lid. The space between the walls of the ball and the walls of the mine was filled with granular materials absorbing shock tectonic waves. The ball itself consisted of several layers of metal. Empty spaces between them, and between the ball and the lid were filled with high-strength concrete.