Century's infrastructure was buried under more than eight metres of ice to provide protection and camouflage.
It could house up to 200 soldiers and was powered by a nuclear reactor, which is believed to have been removed during decommissioning.
However, unsteady ice conditions led to the project's cancellation.
Details were kept secret until 1995, when an enquiry was carried out by the Danish Foreign Policy Institute into the history of storage of nuclear weapons in Greenland.
It was assumed that increasing snowfall and ice would keep the camp safe for millennia, but it is claimed climate change could leave radioactive coolant and thousands of gallons of sewage and diesel fuel uncovered in the next 75 years.
As the ice melts the waste would seep into the ocean, threatening ecosystems of the fish and animals that depend on it.