The Rock of Oëtre (French: Roche d'Oëtre pronounced [rɔʃ dwatʁ]) is situated in the middle of Norman Switzerland, in the commune of Saint-Philbert-sur-Orne, not far from the border between the départements of Calvados and Orne, and almost equidistant from Thury-Harcourt and Écouché.

It is also a popular lookout that gives a broad survey of the wooded groves of the Rouvre, the fast-flowing river in the valley, which can be reached by steps hewn from the rock.

The Armorican Massif does not stop at the border with Brittany, the neighbouring region, but extends to the department of Manche, south-west of Calvados and west of Orne.

Thanks to the environmental awareness of the Orne département, the Rock of Oëtre harbours numerous species of plants and animals rare in France: the spring spergula or spurrey (small white flower), the European green lizard and many species of lichen.

The museum space will be used to let visitors discover the Mountains of Normandy with an interactive landscape, legends and items about the long geological history of the oldest mountains in Europe, the Armorican Massif, from how, two thousand million years ago, they were more than 5 kilometres (3.1 mi) above sea level, to their present 417 metres (1,368 ft).