NASA scientists conducting surveys of arctic ice sheets in Greenland got an unprecedented view of an abandoned "city under the ice" built by the U.S. military during the Cold War.

'We didn't know what it was at first.' NASA aircraft uncovers site of secret Cold War nuclear missile tunnels under Greenland ice sheet

Source: space
Source Link: https://www.space.com/the-universe/earth/nasa-aircraft-uncovers-site-of-secret-cold-war-nuclear-missile-tunnels-under-greenland-ice-sheet