Hardergrat — Interlaken to Brienzer Rothorn

Widely regarded as one of the most aesthetic and challenging ridge traverses in the world, the Hardergrat involves a relentless series of sharp grassy peaks that separate Lake Brienz from the Habkern Valley. The trail is often no more than 30cm wide, with 1,500m vertical drops into the turquoise water below on one side and steep gullies on the other. It is a test of sheer fitness, psychological fortitude (vertigo), and surefootedness. There are no bailout points once you are on the main ridge section; it is a commit-to-finish line.

Sarek National Park is considered Europe's last true wilderness: no marked trails, no cabins, no bridges over raging glacial rivers, and no cell service. However, on the very eastern edge of Sarek lies Mt. Skierfe (1,179m), boasting a sheer 700-meter vertical drop overlooking the braided, turquoise waters of the Rapadalen delta. The view from the top is universally acclaimed as the most beautiful in all of Sweden. To reach it without undertaking a strenuous 10-day survival expedition deep into Sarek, hikers take a multi-day detour off the Kungsleden trail to the STF Aktse hut. From Aktse, Skierfe is climbed as a demanding 10-mile (16km) round-trip day hike through dense birch forests and steep alpine tundra, terminating at the demanding, unprotected cliff edge.