The Collina Reggiana-Terre di Matilde natural and semi-natural protected landscape covers 22,581 hectares on ten municipalities, and safeguards a hill region between the Tuscan-Emilian Apennine ridge and the area at the foot of the Reggio Emilia hills, that includes the drainage basin of the Enza River and - partly - of the Secchia River. The morphology of the area is defined by the Tresinaro, Crostolo and Tassobbio streams. Geodiversity is quite broad: ophiolites in the area of Rossena and Campotrera, where the Reserve of the same name is situated; Salse di Regnano, featuring modest mud volcanoes; the arenaceous cliff of Canossa and its surrounding gullies; the karst morphology of Gessi Messiniani and the vertical Flysch layers of Mt. Duro.