Hammershus, perched on the cliffs of northwest Bornholm in the Baltic, is perhaps Denmark’s best known ruin. It was excavated and renovated at the end of the 1800s up until 1940, but the ruined castle is still shrouded in a mystery with significance to the history of Denmark: who actually built Hammershus, and why?

read more Researchers are trying to solve a Danish castle mystery | ScienceNordic.