The commune of Mortrée is made up of the following villages and hamlets, Mortrée, Méhéran, La Grande Fosse and Saint-Hilaire-la-Gérard.[4]
Mortrée has a total of 10 water courses running through it, three rivers The Orne, La Senneviere and La Thouane. The other seven watercourses are all streams, la Gironde, The Aprel, The Ponts Besnard, La Forêt, The Renardieres, The Cercueil & the vallees.[5]
La carrière des Vaux is a Regional Nature Reserve that is 0.37 hectares in area, making it the smallest nature reserve in France.[9] The reserve was a former quarry that contains many fossils from Conodonts that are naked to the human eye.[10]