The gorges are located in an extraordinary chalky place and extend along 3 km, with overhanging walls being 3-400m high. The name probably comes from the Latin term fragor, in its double meaning of noise and fracture. The abundance of rains in the area determine the enormous quantity of vegetation: mosses, ferns and lichened larches. The Hers, which is the stream running through the area, looks mostly dry as it flows underground and comes to the surface again through various springs. The gorges are protected by the community network Natura 2000.