Shut off from the rest of Europe by the _Pyrenees_ whose high and close
barrier admits easy passage only round its flanks, is the Spanish
Peninsula, which, excepting in its river valleys, and along some parts
of the seaboard, is a continuous highland. A number of mountain ranges,
supporting broad plateaus between, traverse it from east to west. Along
its northern edge the _Cantabrian_ mountains prolong the high line of
the Pyrenees; centrally rise the _Sierras of Guadarrama_ and _Estrella_;
farther south the _Sierra Morena_, and along the Mediterranean border
the _Sierra Nevada_ of Granada. Throughout the summer the table-lands of
_Castile_, bare and treeless, are burned up by the hot sun, but through
the chilly winter they are swept by violent winds. The herdsman who
wears a broad-brimmed hat for protection against the excessive heat
during the day, a few hours later puts on his thick warm cloak; in the
same way, after the almost rainless summer, follows a cold winter with
ice and snow.