Balaklava (Ukraine)
You probably didn’t know that the Ukrainian town of Balaklava has long, cold tunnels hidden in its mountain. It was part of a Soviet project that aimed to build a secret sub base, complete with a water channel and dry dock. The Object 825 GTS was built in 1950s to allow submarines to go up without being noticed.
The network of tunnels included a shelter for nuclear weapons that would protect a nearby city from a nuclear attack. Also, there was an arms depot. It was abandoned in 1996 and then revived at Cold War Naval Museum.
