Cantabrian Mountains (Cordillera Cantabrica in Spanish), a mountain chain which extends for more than approximately 180 miles (300 km) across northern Spain, from the western limit of the Pyrenees to the borders of Galicia, and on or near the coast of the Bay of Biscay. The Cantabrians stretch from east to West, nearly parallel to the sea, as far as the pass of Leitariegos, afterwards trending southward between León and Galicia. Their western boundary is marked by the valley of the river Miño (Portuguese: Minho), by the lower Sil, which flows into the Miño, and by the Cabrera River, a small tributary of the Sil.
Some geographers regard the mountains of Galicia beyond the Miño as an integral part of the same system; others confine the name to the eastern half of the highlands between Galicia and the Pyrenees, and call their western half the Asturian Mountains. There are also many local names for the subsidiary ranges within the chain. As a whole, the Cantabrian Mountains are remarkable for their intricate ramifications, but almost everywhere, and especially in the east, it is possible to distinguish two principal ranges, from which the lesser ridges and mountain masses radiate. One range, or series of ranges, closely follows the outline of the coast; the other, which is loftier, forms the northern limit of the great tableland of Castile and León, and is sometimes regarded as a continuation of the Pyrenees. The coastal range rises in, some parts sheer above the sea, and everywhere has so abrupt a declivity that the streanls which flow seaward are all short and swift.
The descent from the southern range to the high plateaus of Castile is more gradual, and several large rivers, notably the Ebro, rise here and flow to the south or west. The breadth of the Cantabrian chain, with all its ramifications, increases from about 60 m;in the east to about 115 m. in the west. Many peaks are upwards of 6000 ft. high, but the greatest altitudes are attained in the central ridges on the borders of León, Oviedo, Palencia and Santander. Here are the Pena Vieja (8,743 ft.), Prieta (8,304 ft.) and Espinguete (7,898 ft.); an unnamed summit in the Peflas de Europa, to which range the Pea Vieja also belongs, rises on the right bank of the Sella to a height of 8,045 ft.; farther west the peaks of Manipodre, Ubina, Rubia and Cuifla all exceed 7,000 ft. A conspicuous feature of the chain, as of the adjacent tableland, is the number of its parameras, isolated plateaus shut in by lofty mountains or even by precipitous walls of rock.