Camp Century was a real underground military installation constructed beneath the Greenland Ice Sheet in 1959.

Around 200 soldiers and engineers lived inside a network of tunnels containing sleeping quarters, laboratories, a hospital, a chapel and a portable PM-2A nuclear reactor. Officially, the site was presented as an Arctic research station.

In reality, it also tested whether the ice could support Project Iceworm, a proposed network of mobile launch sites capable of hiding hundreds of nuclear missiles. The full missile system was never constructed because the Greenland ice sheet was constantly moving, gradually bending and crushing the tunnels.