Thousands of years ago, people on what is now the Danish island of Bornholm threw hundreds of mysteriously carved stones into a ditch before burying them. The purpose of these so-called 'sun stones', ...
As a volcanic eruption darkened the sun roughly 4,900 years ago, a Stone Age culture sacrificed hundreds of decorated stone plaques to try to coax it back. A trove of engraved stones unearthed ...