The Cantabrian Mountains or Cantabrian Range () are one of the main systems of mountain ranges in Spain. They stretch for over 300 km (180 miles) across northern Spain, from the western limit of the Pyrenees to the Galician Massif in Galicia, along the coast of the Cantabrian Sea. Their easternmost end meets the Sistema Ibérico. These mountains are a distinct physiographic province of the larger Alpine System physiographic division. The Cantabrian Mountains offer a wide range of trails for hiking, as well as many challenging climbing routes. Skiing is possible in the ski resorts of Alto Campoo, Valgrande-Pajares, Fuentes de Invierno, San Isidro, Leitariegos and Manzaneda. Geography The Cantabrian Mountains stretch east-west, nearly parallel to the Cantabrian Sea, as far as the pass of Leitariegos, also extending south between León and Galicia. The range's western boundary is marked by the valley of the river Minho (), by the lower Sil, which flows into the Miño, and by the Cabrera River, a small tributary of the Sil. The Cantabrian Mountains reach their south-western limit in Portugal. 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. In some parts the coastal range rises sheer above the sea, and everywhere has so abrupt a declivity that the streams which flow seaward are all short and swift. The descent from the southern range to the high plateaux 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 mi (97 km); in the east to about in the west. Many peaks are over high, but the greatest altitudes are attained in the central ridges on the borders of León, Asturias, Palencia and Cantabria. Here are the highest peak Torre de Cerredo (), Peña Vieja (), Peña Prieta () and Espigüete (); an unnamed summit in the Picos de Europa, to which range the Peña Vieja also belongs, rises on the right