17 photos show inside an abandoned underground Soviet submarine base that was hidden from the public for decades

Hidden under a 400-feet-thick level of rock, the base is regarded as one of the world's largest secret military objects.Darmon Richter

• Located in Balaklava, a small oceanside town in the Crimean peninsula, lies one of the most top-secret military bases in history.
• Built in 1957, the underground submarine base was used by the USSR as a site to repair and maintain the Soviet Black Sea Fleet, should the country need to attack the USA or other countries.
• It was believed to be virtually indestructible and 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 Soviet-era submarine base was converted into a museum in 2003.

While all abandoned places have interesting histories, this deserted Soviet-era submarine base has quite the story to tell.

Hidden away from the public for decades, this top-secret military base was used to maintain and repair the Soviet Black Sea Fleet, an advanced military fleet of submarines ready for war at a moment's notice during the Cold War.

After it was left abandoned at the end of the 20th century, its haunting hallways and dimly lit corridors remained empty. However, after being gifted to the Ukrainian Navy in 2000, the base was converted into the Balaklava Naval Museum, allowing visitors to step inside the abandoned building for the first time since the end of the war.

Here's a look inside the abandoned secret Soviet submarine base.