M., and includes the greater part of the vast plateau of Old Castile, between the watersheds of the Cantabrian Mountains, on the north, and the Guadarrama, Gredos, Gata and Estrella ranges, on the south.
The last four rocks occur as a volcanic series distributed in three chief districtsthat of Cape Gata, including the south-east of Andalusia and the south of Murcia, that of Catalonia, and that of La Mancha.
On the west another rough and hilly tract, similar to that which divides it from the Sierra de Guadarrama in the east, separates it from the Sierra de Gata, the westernmost and the lowest of the Spanish sierras belonging to the series.
The Sierra de Gredos has a road across it connecting Avila with Talavera de Ia Reina by the Puerto del Pico; but for the most part there are only bridle-paths across the Gredos and Gata ranges, and no railway crosses either of them, although the line from Plasencia to Salamanca skirts the Sierra de Gredos on the west.
Wide at its entrance, and terminating, on the east, in the Cabo de Gata, the southernmost point of eastern Spain.