Barbarossa Cave

Miners broke into the cave in 1865 while prospecting for copper. It formed in anhydrite, a calcium sulphate rock that swells and turns to gypsum when it takes up water, a process that lifts and folds the ceiling; the result is sheets and lobes of grey rock hanging in shapes unlike the dripstone of limestone caves, with underground lakes reflecting them. Only a handful of caves worldwide are open to visitors in this rock type. Legend places the sleeping emperor Frederick Barbarossa under the Kyffhäuser hills, which gave the cave its name after opening; the story is medieval and attaches to several locations.

What you actually see

• The anhydrite ceilings - grey rock lifted and folded by swelling.
• The underground lakes - still water reflecting the hanging sheets.
• The rock type - a cave form open to visitors in very few places.
• The Barbarossa legend - a medieval story attached after the 1865 discovery.

When to go

Year-round; the cave holds about nine degrees and tours run at set times. It is drier than limestone caves but still cool. Booking helps in school holidays.

Honest expectations

There is no dripstone of the usual kind, which surprises visitors expecting stalactites. Entry is guided only with steps. Photography rules apply.

Nearby

Bad Frankenhausen lies east; the Harz is north.