Located in the southwest of Galicia, in the region of Valdeorras, the municipality of O Barco occupies part of the river valley of the Sil River and the raised lands that surround it. O Barco is the capital of the Valdeorras region and is the nucleus for shopping and services.

O Barco de Valdeorras, capital of the region and site of the area’s administrative services, consists of 24 population centres. With an extension of 84 km2, it borders the Sierra del Courel to the north, the municipalities of Rubia and Carballeda to the east, that of Vilamartin to the west, and to the south it borders the Sierra del Eje, which ends in the Trevinca Massif, home to the highest peaks in Galicia.

Romanization was intense in this territory, which was strategic and rich in minerals. Among the gold deposits of Lanas Médulas (Bierzo) and Montefurado (Lugo) there are many traces of the extractive activity carried out in that historical period. The Roman through-road Via Nueva (the 18th road of the Antonine Itinerary), which linked Braga and Astorga, passed through Valdeorras.

In the Middle Ages the Lordship of Valdeorras was already administered by different noble families. One remaining landmark of that time is the Fortaleza del Castro (Castro Fortress), protected as an Asset of Cultural Interest since 1994, categorized as a monument.

The economy revolves around slate. Valdeorras has the highest concentration of quarries in Spain. Viticulture is another of the important sectors, with the cultivation of native varieties such as godello and mencía for the elaboration of high quality wines becoming increasingly significant. In O Barco there is a wine cooperative and several wineries.