The Cantabrian mountains, in Spanish the Cordillera Cantábrica, stretch more or less parallel to the northern coast of Spain running some 500km from the western Pyrenees, through the Basque country, Cantabria, Castille and León, Asturias and into Galicia. They effectively separate Green Spain from the high plains of the Central Meseta and are the reason why the former receives so much rainfall from the prevailing west/north-westerly weather fronts.

They are composed of mostly limestone, conglomerate, shale, quartz, sandstone and granite, giving rise to many interesting rock formations such as this ridge of limestone outcrops that brings to mind the back of a Stegosaurus.

From a distance lumps of conglomerate appear green because of the lichens growing on the surface.

In places the history of the sedimentary processes and the contortions in the rock are vividly obvious.

Excluding the Picos de Europa, the highest point in the Cantabrian mountain chain is Peña Prieta, which at 2,539m rises from the central area of these mountains in the province of Cantabria near the border with Castile-León.

See also the San Glorio pages for more on the Cordillera Cantábrica and it's flora and fauna.