Location: occupies the municipalities of Carballeda de Valdeorras, A Veiga, Viana do Bolo, O Bolo and Manzaneda.
Surface area: 24,860.33 hectares.
At the confluence of the O Eixe, Calva and Segundeira mountains and bordering Castilla y León, the Pena Trevinca mountains, also known as “Trevincas”, form the only mountainous massif of Galicia formed by mountains that exceed 2,000m altitude .
The massif reaches its maximum height (2.127m) at the top of Pena Trevinca, in the municipality of A Veiga becoming the highest point of Galicia. Also of great importance are the heights of Pena Negra (2.123m) and Pena Survia (2,122m).
Pena Trevinca also enjoys incredible natural lagoons and other elements of glacial origin such as those of A Serpe and Ocelo.

This massif is also distinguished by a varied and unique flora highlighting the Teixadal de Casaio, a unique forest in Europe formed by a group of approximately three hundred yew trees and considered the best preserved peninsula.
In relation to the fauna of the place, it is worth noting the presence of more than 88 species of birds, of which the following are especially noteworthy: Royal Eagle, Griffon Vulture, Black Vulture, Peregrine Falcon, Pale Harrier, Ceny Harrier, Pardal Perch Quail, Royal Owl, Totovía, Common Skylark, Campybug, Red-billed Warbler, Redneck Chow, Common Kestrel etc.
The mountains of Pena Trevinca were included by the Department of Environment in the European Network Natura.