Lake Oeschinen was formed by several landslides from the flanks of the Fründenhorn and the Doldenhorn. Since 2007, Lake Oeschinen has been part of the extended UNESCO World Natural Heritage Site Swiss Alps Jungfrau-Aletsch.
An estimated 9000 years ago, large rockfalls occurred in Kandersteg, including from the Birre and the Fislisstock. The huge landslide from the Birre must have sealed off the valley basin of Kandersteg with a huge dam, behind which the Kander and the Oeschinenbach were dammed to form a lake until a mighty debris flow opened up the valley again.
The mountain lake at 1580 metres above sea level was discovered by tourism early on. In 1892, David Wandfluh built a coffee house with a hay store at the lake, entertained hikers and also took them on a boat trip across the idyllic lake. Today, the Berghotel Oeschinensee is run by the fifth generation of the Wandfluh family.
Lake Oeschinen was also formed by a landslide. In the process, the debris masses with a volume of well over a hundred million cubic metres that broke off at the Doldenhorn at an altitude of 2100 metres formed a natural dam. The rock material is still permeable to water today, which is why Lake Oeschinen is drained underground.