Like many cathedrals in Spain, the Primate Cathedral of Saint Mary of Toledo was built on the site of a former mosque, and took more than 200 years to complete. It is one of the finest examples of Gothic architecture in Europe and is one of the three 13th-century High Gothic cathedrals in Spain. In fact, this must-see cathedral is considered to be the most important. Not to be missed is the cathedral’s sacristy, which contains paintings by El Greco, Caravaggio, Titian, Raphael and Velazquez.