Oeschinensee

The Oeschinensee lies at 1578 metres above Kandersteg, in the Bernese Oberland. It covers 1.1 square kilometres, measures about 1.6 kilometres long by one kilometre wide, and reaches 56 metres in depth. A cirque of peaks that all pass the 3000-metre mark overlooks it: the Blüemlisalp, the Oeschinenhorn, the Fründenhorn and the Doldenhorn. The difference in altitude between the water surface and these summits thus exceeds 1400 metres.

The lake is held back by rock masses detached from the Fründenhorn and the Doldenhorn, which dammed the valley. That dam explains a peculiarity: the lake has no visible outflow. The Öschibach disappears beneath the fallen blocks and continues its course underground, so that the water leaves the basin without being seen to go.

The lake has been part of the UNESCO World Heritage property Swiss Alps Jungfrau-Aletsch since 2007. The property had been inscribed in 2001 under the name Jungfrau-Aletsch-Bietschhorn, over 53,888 hectares, before being extended in 2007 to 82,388 hectares; its perimeter covers the Aar massif, of which the Oeschinensee marks the western limit. The centre responsible for its management describes an ensemble of 824 square kilometres spread over the cantons of Bern and Valais.

Why this place is remarkable

A rockfall-dammed lake at 1578 metres, without surface outflow, backed by walls that rise more than 1400 metres above it, and lying exactly at the western limit of the UNESCO Jungfrau-Aletsch perimeter.

History and origin

Dammed lake formed by rock collapses from the Fründenhorn and the Doldenhorn. Area 1.1 square kilometres, length 1.6 kilometres, width 1 kilometre, maximum depth 56 metres, mean level at 1578 metres. No surface outflow: the Öschibach passes underground beneath the fallen blocks. The lake has been included since 2007 in the World Heritage property Swiss Alps Jungfrau-Aletsch, inscribed in 2001 over 53,888 hectares and extended in 2007 to 82,388 hectares.