If not in summer, then Andalusia. If summer, then either the area north & west
of Madrid (Avila, Segovia, Salamanca, Coca, Santiago de Compostela, Picos de Europa, Leon, Covadonga, Santander, Burgos, etc), or central Spain (Madrid, Toledo, Cuenca, Avila, Segovia, El Escorial, Valle de los Caídos, Consuegra, Siguenza, etc).