The Arz ValleyNatura 2000 area
©G. Sourget

The Valley of the Arz

Rochefort en Terre, in addition to its preserved heritage, can count on an environment that is conducive to a change of scenery: the Arz Valley. You will be able to discover at your own pace Les Grées as well as the old Ardoisières.

The Arz Valley

Two spaces, one natural magic

To the north

There are little marked reliefs, this is a bocageous area surrounded by sometimes quite large agricultural plots. It is a place of livestock and cultivation. The Arz River crisscrosses the landscape, forming numerous meanders and collecting several tributaries descending from the neighboring reliefs. This part of the valley rises and rests on the granitic massif of the Landes de Lanvaux.


Corresponds to a line of schist ridges oriented parallel to the Arz valley. The relief is markedly more pronounced with steep areas. It is a landscape covered with moors and woodlands from which many rocky spurs emerge. Formerly exploited, many old slate quarries can still be seen here. The summit of the site is located north of the commune of Pluherlin and culminates at 120 meters in altitude.

The species

Vegetable and animal

16 plant and animal species and 9 habitats of community interest identified on the Arz Valley Natura 2000 site.
Protected species include 7 mammals including 6 bats, 4 fish, 3 invertebrates and 2 plants.

6 bats and an otter represent the mammals: The Great Murre, Scissor-eared Murre, Bechstein’s Murre, European Barbastelle, Little and Greater Rhinolophus, European Otter. In the aquatic environment, are found the Planer lamprey, the sea lamprey, the Common sculpin and the Atlantic salmon. Invertebrates and plants are also given special care regarding their preservation: the Great Capricorn, the Thin-bodied Cordillera, the Mercury Agrion, the Swimming Flute, and the Trichomanes. They are rare or endangered species and as such benefit from specific protections under Natura 2000.

You can observe them on a hike or a nature walk offered by the region’s Nature associations. You can procure the hiking sheets at our Tourist Offices.

All species

A European network

of sites of ecological interest

Natura 2000 is a European network of sites of ecological interest with animal and plant species considered rare and threatened by the European Union. It currently represents 12% of the French national territory. Natura 2000 has two objectives: to preserve biological diversity and enhance the natural heritage of our territories. The ultimate goal is to achieve to allow this environment toperennialize in the long term.

The Arz Valley are 1,234 hectares of which 300 in the Natura 2000 perimeter where 15 animal and plant species live in 9 different forms of habitat (dry moorland, forest, rare grasslands, agricultural…).
This area extends between Rochefort-en-Terre, Pluherlin, Molac, Malansac and St Gravé around the river Arz. The approach of preservation of these habitats and these species is established by considering the human activity. It is not a setting under bell of a predefined space. The site is part of the Zone Naturelle d’Intérêt Écologique Faunistique et Floristique des Landes de Lanvaux which extends from St Jacut les Pins to Plumelin.

Further information on Natura 2000