The Nyer Reserve is a constituency of Py and Mantet that covers an area of 2,200 hectares with a sprawl from 730m to 2663m on its northern entrance that is characterized with spectacular gorges. The domain belongs to the geological unit of the massif of Carenca that consist Augen gneiss with three sub sectors of the gneiss that are injected alkaline granites and have an impressive gorge facial. The forest is formed around the cliffs and they are the main attractive interest of the protected site, they landscapes consist of Mantet valley that has more hardwood than softwood, while the Carenca is dominated by the mountain pine.

This Nyer Reserve site is used for campaigning against soil erosion in these valleys and torrential dynamics that requires a scientific monitoring. This reserve is also a home of many habitants like the moor, rock, wetlands, and grasslands that compose diversity by explaining the existence and originality of flora and remarkable for strong in tension. The diversification of ecological niches and artificial site that allows the life of rich and varied fauna and the reserve site are the world full of chamois, forest cats, ground hogs and some nest that are rarely enigmatic Pyrenean muskrat, Genet and bats.