Climbing the 'U-Boot' section on the Randkluftsteig in the Dachstein Mountains is a truly unique alpine experience. After crossing the vast Dachstein glacier, you reach the base of the Hoher Dachstein. The 'U-Boot' itself is a narrow, almost tunnel-like rock formation you have to squeeze through or climb over. Despite its short length, the moves required to navigate this feature, especially with a backpack, can certainly feel like a solid 4+ grade, demanding careful foot placement and body control. It's an exposed and thrilling moment, offering a brief but intense challenge amidst the grandeur of the limestone peaks. The views are incredible, making this short, distinctive section a memorable highlight of any ascent of the Hoher Dachstein.