Accessible at the end of two panoramic walks and a cable-car ride of dizzying views, the caves are well worth the effort. At an altitude of 1 664m on the west face of Hochkogel, 1 000m above the Salzach Valley, these caves, comprising some 42km of galleries, are one of the most impressive subterranean networks in the world. They are famous for their amazing glacial décor, the result of winter freezing (causing water in the rock to turn into ice and split it).