julio 2002

The most notable rivers are: the Agüera, the Ason, the Miera, the Pas, the Besaya, the Nansa and the Deva (that it shares with the Principality of Asturias).
The Ebro river is the most abundant river on the Spanish mainland, springing from Fontibre, it does not have much water as it rises from the Mediterranean basin.
The geography of the region is dominated by the most important hydrographical vertex in the whole of Spain: Peña Labrada, where the Cantabrian, the Duero and Ebro basins all meet.

"Source: Web server of Instituto de Turismo de España"