CAVE OF LUMMELUNDA (LUMMELUNDAGROTTAN)

A dozen kilometers north of Visby, Lummelunda Cave, carved by sea currents up to 3 km inside the rock, is open to the public. The explored part of this karst cave is almost 4.5 km long, making it one of the longest caves in Sweden. Although the entrance to the cave has been known for centuries, the main part was discovered by three teenagers in the 1940s-1950s. It is visited by 100,000 people a year.