One of the most impressive unfinished Soviet military installations is hidden in Crimea. Spanning over 10 kilometers of tunnels and featuring a 4-story bunker buried 180 meters beneath solid bedrock, this is the Black Sea Fleet’s Reserve Command Post—also known as «Alsu-2,» «Height 495,» «The Den,» and «Object 221.» Designed as a shelter for Soviet leadership in case of nuclear war, the facility was meant to ensure survival and command capabilities if Crimea came under attack.