The forest of Grésigne, with its 3600 hectares, is one of the largest oak forests in Europe, in a logic of sustainable development, the massive Grésigne was classified by the European Commission as a natural area of ecological, faunistic and flora in the Natura 2000 network.
The weakness of human occupation of the forest allows Grésigne to host a rich fauna in cervids (deer, roe deer), wild boar, small mammals, carnivores (weasels, martens, genets, wild cats), and more than one hundred species of nesting birds (booted eagles, hawk, buzzard, woodpecker, warbler ...) and many species of beetles, among the many varieties of wild plants on the edge of the Grésigne, orchids are probably the most remarkable.
The Grésigne forest is an ideal place for leisure nature, and is studded with a wide variety of trails leading you to a discovery to the other where you show all turns an untouched nature
In season, everyone rushes to pick mushrooms: ceps, chanterelles, trumpets of death ...
The Wall Louis XIV, which girds the forest, is still visible in places and passes a few meters from the place called The Bouygue (on the town of Penne) is also close the mythical "Pech Aguze", the rock of the Eagles The highlight of the area (491 m).
From mid-September to mid-October, at dusk, one attends the show always impressive slab of deer: the hoarse cry led by deer to attract females and demonstrate its desire while separating males competitors.