The mountains are upside down
Along the clearly exposed line of the Glarus Overthrust, 250 - 300 million year-old Verrucano rocks were thrust up over younger, 35 - 50 million year-old flysh rocks. Extraordinarily, the younger material lies on top - which was long a riddle for geologists and so unusual that on 7th July 2008 the area was designated as one of the UNESCO World Heritage Sites.
In no other area, worldwide, can the phenomenon of mountain building be so clearly observed. The 300 km2 area is distinguished by the combination of the clear exposure of the phenomenon in a mountain setting, its history of study and its ongoing contribution to geological sciences.
The UNESCO World Heritage Site has many more interesting features alongside the Glarner Overthrust: unspoilt countryside, a wealth of Alpine plants and animals, the oldest resettled ibex colony in Switzerland, nationally important moors and swamps and and unusually high concentration of geotopes (geological sites). Geotopes are protected geological sites which illustrate the history of the earth, such as the Lochsite, the Tschingelhoren mountains with Martinsloch, the copper quarry on the Mürtschenalp, the landscape in the depths of the Murgtal valley, which was formed by ice-age glaciers, and the Segnesböden.