The municipality of Mieres is situated in one of the most peaceful parts of La Garrotxa, between Santa Pau and Banyoles. It combines the settlements of Brugueroles, Samuntà de Baix, Samuntà de Dalt and Ruïtlles.

Mieres is bounded to the southeast by the serra de Portelles and Rocacorba mountain ranges and on the west by the mountains of Finestres, and on the north by the mountains of Ventatjol and El Coll. The source of the river Mieres, also called Merdançà, is in Mieres valley and flows into the river Tort.

Ruïtlles, its church and those of Sant Pere, Santa Maria de Romeria, Santa Maria del Freixe and the Barri de la Sallera are some of the municipality's most noteworthy places.