4,900 years ago, a Neolithic people on the Danish island Bornholm sacrificed hundreds of stones engraved with sun and field motifs. Archaeologists and climate scientists from the University of Copenhagen can now show that these ritual sacrifices coincided with a large volcanic eruption that made the sun disappear throughout Northern Europe.

Last month Newsweek talked to archaeologist Matthew Larsen (Theology and School of Archaeology, UCPH) who has identified remains of a 1,600-year-old Roman prison at the archaeological site of Corinth, Greece.