Leaving the historic little town of Unterseen, we pass through modern residential areas lining the banks of the River Aare and make our way to the ruins of Weissenau Castle where the Aare flows into Lake Thun. We follow the line of the Aare delta, passing a nature reserve and reaching the mouth of the River Lombach at Neuhaus. Bypassing the foot of the Niederhorn, we head for the bay of Sundlauenen, a popular day-trip destination. After passing through the Sundlauenen delta, we move back up to Thunerseestrasse. Crossing this, we reach the start of the impressive Luk-Treppe, the pilgrim’s path hewn into the rock that leads up to the entrance to the popular St. Beatus Caves, where Saint Beatus is said to have once lived. After this, much of the route passes through woodland. «Widmannsplatz» brings us to a viewing turret, where we take a break. The route to Merligen then crosses the Thunersee–Beatenberg funicular, shortly after which we reach a stage location where we need to decide whether to continue along the right bank or take a boat to Spiez.
Interlaken/Unterseen - Aare - Ruine Weissenau - Unteres Stadtfeld - Neuhaus - Sundlauenen - Sankt Beatus Höhlen - Balmholz - Merligen