Castile-La Mancha and Castile-León are like parentheses around Madrid, one north and one south, split by the Guadarrama mountains just north of the capital. The name Castilla refers to the great east-west line of castles and fortified towns built in the 12th century between Salamanca and Soria. Segovia's Alcázar, Ávila's fully intact city walls, and other bastions are among Castile's greatest monuments. Many have been converted into splendid hotels.