The Vandals overpowered the Romans in 435 AD. For the next 800 years, rule over the city changed hands no less than a dozen times. Soon after it was conquered by King Alfonso X of Castile in 1245, he ordered the building of a large keep at the summit of Mount Asclepio (now Cerro de la Concepción). Stones from the adjacent Roman Theater were plundered for its construction. This arch is Puerta de la Villa, the entrance to Castillo de la Concepción in Torres Park. The locals call it Castillo de los Patos (Castle of the Ducks).