f Leitariegos,
afterwards trending southward between Leon and Galicia. Their western
boundary is marked by the valley of the river Mino (Portuguese Minho),
by the lower Sil, which flows into the Mino, and by the Cabrera, a small
tributary of the Sil. Some geographers regard the mountains of Galicia
beyond the Mino 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 Leon, 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 streams 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 Leon, Oviedo, Palencia and Santander. Here are the Pena
Vieja (8743 ft.), Prieta (8304 ft.) and Espinguete (7898 ft.); an
unnamed summit in the Penas de Europa, to which range the Pena Vieja
also belongs, rises on the right bank of the Sella to a height of 8045
ft.; farther west the peaks of Manipodre, Ubina, Rubia and Cuina all
exceed 7000 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. At the
south-western extremity of the chain is el Vierzo, once a lake-bed, now
a valley drained by the upper Sil and enclosed by mountains which
bifurcate from the main range south of the pass of Leitariegos--the
Sierra de Justredo and Montanas de Leon curving towards the east and
south-w