This drinking water reserve, located 2 km from the source of the Sienne, covers 66 hectares. About 16,000 m3 of water are withdrawn every day to meet the demand for drinking water.
Today, only one quarry still extracts the “Bleu de Vire” granite. It is used to produce cobblestones for pedestrian areas in cities, tombstones for funerary monuments and for high technology …
There, the meadows are dotted with granite balls called "oxen". Large granite blocks with rounded shapes outcrop there. They result from the weathering of the granite into balls under the action of infiltration water.
Large blocks of granite with rounded shapes outcrop in the meadow. Called "oxen", these balls of undecomposed granite were cut or pushed back to the edges of the fields and formed stone slopes.