On September 2, 1806 heavy rains triggered a landslide from the Rossberg which destroyed Goldau and the adjacent villages of Busingen, Röthen and Lauerz. The landslide comprised 40,000,000 cubic metres of material, with a mass of 120,000,000 tonnes. Part of the mass hit Lake Lauerz (which had been created by an even larger landslide in the 14th century), and the resulting tsunami-like displacement wave caused more devastation towards Seewen. The event destroyed 111 houses, 220 barns, and two churches in a disaster area of about 20 km2 parts of which were covered with debris to a height of 30–70 metres. It resulted in the confirmed death of 457 people.
A museum outside the Natur- und Tierpark shows findings and photos of this natural disaster (Wikipedia).
I visit this park regularly with my children. In the cold and wet seasons rocks and wood are particularly overgrown with moss. The results partly looks bizarre and beautiful, created by mother natur