Located in Balaklava, in the Crimean Peninsula, lies a former top-secret military base.
It was believed to be virtually indestructible and able to withstand a direct hit by a nuclear bomb.
The Soviet-era submarine base was converted into a museum in 2003.
Balaklava is a small oceanside town in the Crimean peninsula, part of the city of Sevastopol.
Under ground in Balaklava Bay lies one of the most top-secret abandoned military bases in history.
Balaklava was selected as the location for the USSR's naval military base because the area could not be seen from the open sea.
According to Ukraine.com, the discreet location made it a perfect spot for the top-secret naval base.
Balaklava itself has functioned as an active military port for centuries.
However, according to The Bohemian Blog, the Crimean submarine base was not constructed until 1957, during the height of the Cold War.
The base is buried under nearly 400 feet of rock.
The top-secret base was built by the USSR as a site to repair and maintain the Soviet Black Sea Fleet.
In 1957, Soviet leader Nikita Khrushchev challenged the USA to a "peaceful shooting match."
According to Politico, Khrushchev claimed the Soviet Union had missile superiority.
Under the orders of Joseph Stalin, the naval base was constructed to be ready for nuclear war at any moment. It was built to be virtually indestructible.
According to The Bohemian Blog, the base took four years to construct and required the stealthy removal of more than 120 tons of rock in order to make the tunnels accessible to the water.
The base, known as Objekt 825, was also created to house a fleet of USSR submarines should the country wish to make a retaliatory nuclear strike against the USA.
In the case of a nuclear attack, personnel had enough resources at the base to survive for 30 days.
Each compartment of the high-security naval base was obstructed by large doors to ensure maximum security. According to Discover Ukraine, the compartments were also blocked by gates made of steel and covered in a layer of concrete.
According to Ukraine.com, the base was equipped with adequate ventilation, food, fuel supply, water, and electricity for the 1,500 military personnel at the base, as well as the inhabitants of Balaklava, should a nuclear attack occur.
The base was reportedly able to withstand a direct hit by a nuclear bomb of up to 100 kilotons, roughly five times the power of the bomb that was dropped on Hiroshima.
The base is regarded as one of the world's largest secret military objects.
Sections of the base are connected by a nearly 2,000-foot-long deep-water canal.
According to Discover Ukraine, the canal is located underneath the thick layer of rock.
The base had a number of different uses.
According to Discover Ukraine, the base housed repair shops, storehouses for torpedoes and other weapons, command posts, anti-nuclear shelters, and administrative offices for military personnel.
The submarine base, as well as the entire town of Balaklava, was under strict lock and key.
According to The Bohemian Blog, all visitors, including even the family members of those who worked at the base, needed "extensive documentation" in order to enter Balaklava.
After the fall of the USSR, the base remained in operation for years until it was decommissioned.
Unlike many other military facilities, the naval base at Balaklava operated beyond the fall of the USSR.
The decommissioning process began in 1993.
The very last Russian submarine was removed from Balaklava Bay in 1996, five years after the fall of the Soviet Union.
After the base was abandoned, many people forgot about the eerie symbol of the militaristic USSR.
Balaklava was now unrestricted, and those who moved to the town had little knowledge of the underground base. However, some managed to sneak down into the abandoned base and explore.
Following its decommission, in 2000, the Russian Federation gifted the base to the Ukrainian Navy.
According to The Bohemian Blog, the submarine base officially opened to the public in summer 2003.
The base is now known as the Balaklava Naval Museum Complex.
Guests can step inside the base's abandoned walls to take photos and learn about its history.
Visitors to Balaklava can now travel through the base's dimly lit tunnels and view artifacts and memorabilia from the time of the submarine base's operation.
The conversion of the base into a museum effectively allows visitors to step back in time to the days of the Cold War. The museum is currently open for tour groups after a period of reconstruction.
Read the original article on Insider