While scanning the frozen surface of northwestern Greenland this year, NASA scientists stumbled across a "city under the ice" from the paranoid years of the Cold War.
The structure was Camp Century, an abandoned Arctic military research base run by the US between 1959 and 1967 during the Cold War. It was the hub of Project Iceworm, a plan to install a network of nuclear missile launch sites hidden amid the Arctic Ice Sheet that could survive a first strike from the Soviet Union.
Nuclear missiles never made it to the camp, fortunately, because they couldn’t get permission from the Danish government, which still holds sovereignty over Greenland. However, the complex was powered by a nuclear reactor, which left behind a large amount of radioactive debris, as well as loads of chemical and biological waste.
IFL Science's most recent item on this is here: https://www.iflscience.com/a-nuclear-city-under-the-ice-revealed-by-nasa-scans-over-greenland-76983 - and a background feature posted in 2016, is here: https://www.iflscience.com/top-secret-cold-war-nuclear-missile-base-unearthed-by-climate-change-37242
