The Cavorco da Fervenza Grande, a tributary of the river Visuña whose waters flow into the river Selmo, is located in San Pedro de Hórreos, in the town of Folgoso do Courel.

Cavorco is a Galician word that means: "a deep path between mountains along which a water channel for irrigation flows". The waterfall, which falls from a great height, can be seen from the DP-50-01 road to Visuña. It is almost impossible to get close to it, as it is located in a gorge with an enormous cliff.