Accompanied by blinking red lights and deafening sirens, hidden deep below the ground in the centre of Moscow, lay home to Russia's nuclear button.
It might sound as cliche as a James Bond film, but that button would have changed the world as we know it - had someone pushed it.
Safely tucked away from prying eyes, Bunker 42 was Joseph Stalin's expansive nuclear facility built by the Soviet Union during the Cold War, when the threat of nuclear warfare with the United States was a very real and terrifying, prospect.
Stalin ordered the facility's construction in 1951, and it was one of the most top secret military facilities in the heart of the former-USSR.
Lined with four narrow "tubes" that connect tunnels and rooms totalling 7000 sq m, the bunker is hidden at a depth of 65m underground (deep enough to survive a nuclear attack) and was used as a "communications headquarters for the country's leadership and military top brass".
The complex was up and running by 1956, designed to survive a thermonuclear war with the United States, who were stockpiling nuclear weapons at the time.
It was officially called the "Tagansky Protected Command Point" because its workers entered via a secret door at Tagansky Station on the Moscow Metro.
At its peak, more than 2500 people worked at the facility.
If a nuclear bomb were launched from the facility, it would take a mere 33 minutes to fly over Russia and the Arctic, until it hit its target in the US.
It was fully equipped in case of a nuclear attack; food, fuel and air and water regeneration systems that could provide enough to live on for at least 3000 combat duty personnel for three months.
By the late '80s though, the threat of nuclear war weakened and the site had deteriorated and "lost its key importance for ensuring the country's defence," its website reads. It was declassified in 1995 and in 2006, the Russian government sold the complex to a private company for 65 million rouble ($AU1.25 million).
Today, the complex functions as a museum and entertainment complex, but more importantly, according to the Russians, "Bunker-42 is a symbol of power and might of our Motherland. This is an object of our pride and admiration by the state, which could create it.
"And yet, this is a reminder about the vanity of any arms race and about the need for peace on Earth."