NASA has released photos of a US military base that was built in the ice in Greenland during the Cold War and later abandoned. The photos were captured by happenstance while NASA scientist Chad Greene was flying over the Greenland Ice Sheet.

Scientists now have a clearer picture of Camp Century, an abandoned U.S. military base long hidden under the ice in Greenland, thanks to a NASA research team's good luck.

As a NASA science flight was flying over the Greenland ice sheet this spring, a surprise popped up on a specialty radar: a hidden Cold War city more than 100 feet beneath the ice.