Balaklava, Ukraine
The Ukrainian town of Balaklava is so picturesque that you would likely never have guessed that cold, eerie, and long tunnels exist inside the mountain. This was part of the Soviet project to create a secret submarine base with a dry dock and water channel. It used to be called Object 825 GTS and was built in the ‘50s so the submarines could come up without being spotted. The tunnel network came with a nuclear shelter that would protect the nearby town in case of a nuclear attack. There was also a weapon storage facility there. In 1996, it was abandoned and then repurposed into the Cold War Naval Museum.
Balaklava
Object 280
The Soviet Naval Museum complex in Balaklava also came with a massive technical and repair base code called Object 280. This complex was made to maintain and store the nuclear arsenal being transported to the tunnels in the Tavros mountain at the time. Object 280 was basically a special tunnel that they used to load equipment into during the wartime. This made perfect sense since Object 825 GTS was basically created to store, maintain, and repair the vessels from Project 613 and 633.
Object 280
