Castle
Castillo de Gormaz
Some 14km south of El Burgo de Osma, one of Spain's most remarkable castles rises above the virtual ghost town of Gormaz (population 21). Built by the Muslims in the 10th century and reportedly the largest Muslim fortress in Europe, the castle was for centuries an important bastion along the frontier between Islamic armies and the Christian forces of the Reconquista. Most of its 21 towers remain and the walls stretch for over a kilometre.