Between 1975 and 2013, the exploitation of white clay by humans dramatically changed this forest environment. At the origin of this supernatural landscape, this old kaolin quarry produced a beautiful white earth intended for the manufacture of porcelain, tiles, bricks, and cosmetic and pharmaceutical products. To extract and process the kaolin, operators moved thousands of cubic meters of material by digging up to 40 meters deep. After the end of the industrial exploitation of white clay, the vegetation regained its rights and this huge open-air quarry filled with rainwater, giving rise to a deep artificial lake. This new environment is still very young and the acidity of the soils of the different geological layers prevents any development of aquatic life in the lake (algae, fish, amphibians). The water is crystal clear, transparent, and has no suspended matter that can absorb light. This is fully reflected in the lake which thus sports a shades of blue, from turquoise to azure blue, to the delight of walkers and nature lovers.
Two trails allow you to discover this disconcertingly beautiful site: the Grand Bois du Marais circuit and the Guêpiers circuit.