The municipality of Mieres is located in one of the quietest areas of Garrotxa, between Santa Pau and Banyoles. It includes the towns of Brugueroles, El Samuntà de Baix, El Samuntà de Dalt and Ruïtlles.

Mieres is bounded to the south by the Portelles mountain range and the Rocacorba massif, to the west by the Finestres mountain range and to the north by the Coll and Ventatjol mountain ranges. The Merdançà and the Ritort drain the Mieres valley and pour their waters, respectively, into the Ser river and the Sant Miquel de Campmajor stream.

Ruïtlles, the church of Ruïtlles and the churches of Sant Pere, Santa Maria de Romeria, Santa Maria del Freixe and the Barri de la Cellera are some of the most prominent places in the municipality.