CAVES OF THE ICE GIANTS (EISRIESENWELT)

It is the largest glacial cave in the world, so for that reason alone, it is worth a visit. You can get there by cable car. It takes half a day, warm clothes (!) and good shoes, even an ice axe and crampons for people with uncertain balance. On site tea room and restaurant. Reduced rates if you buy your tickets online. If you don't take the cable car, it's cheaper, but you'll have to walk about 20 minutes.