Italy
An underground, formerly classified submarine base that was operational until 1993. The base was said to be virtually indestructible and designed to survive a direct atomic impact. During that period, Balaklava was one of the most secret residential areas in the Soviet Union. The visit consists of a
guided tour (in Russian) of the underground galeries and impressive underground channel of the naval base. It lasts about one hour. There are two itineraries but the alternative itinerary is only available if a minimum number of visitors is reached (about 18). There are a lot of explanatory signs, but in Russian and Ukrainian only (except for a few weapons with explanatory notes also in English).
Listen to the audio guide for Balaklava Naval Museum Complex Free on WIP — starts by itself when you arrive, even with the screen off