Grossglockner — The Gamsgrubenweg Trail

Starting at the end of the high-alpine Grossglockner High Alpine Road (Kaiser-Franz-Josefs-Höhe), the Gamsgrubenweg is a masterpiece of high-altitude trail engineering. It contours high above the Pasterze, Austria's largest glacier, leading into the heart of the Hohe Tauern National Park. The trail passes through several tunnels built to protect hikers from rockfall, eventually opening into the vast, tundra-like 'Gamsgrube' (Chamois Pit), a special protection zone where the rare flora and fauna of the high Alps thrive in the shadow of the Grossglockner (3,798m).

The Kīlauea Iki Trail on the Big Island of Hawaii offers an otherworldly experience: the chance to hike directly across a solidified, still-steaming lava lake inside a volcanic crater. In 1959, this crater erupted sustainedly, shooting fountains of lava 1,900 feet into the air and filling the basin with a fiery lake. Today, the surface has crusted over into a jagged floor of jet-black 'pahoehoe' (smooth) and 'a'a' (sharp) lava rock. The hike begins in a dense, lush, tropical rainforest of native ohia trees and giant hapu'u tree ferns along the crater's rim before plunging 400 feet down the steep walls. Hikers then follow a path marked by stone cairns ('ahu') directly across the desolate, cracked, steaming expanse of the crater floor, walking over active volcanic vents.