The site of the Simancas castle was at one time a Moorish fortress. In the 15th century the House of Enríquez constructed a new fortification on top of the existing ruins, restored the Moorish walls, and added a chapel. The new castle was seized by the Spanish Crown during the reign of the Catholic Monarchs and turned into a prison. In 1540 the Archivo General de Simancas was established in the castle, the first official archive of Castile. Felipe IItransformed the castle into General Archive of the Kingdom, which housed one of the most important archives in Europe with 35 million documents. The castle was put under the protection of the Spanish government in 1949. In 1952 renovations were enacted to reduce risk to the archives. The castle is now open to tourists and researchers.
The castle's foundation, walls, battlements, gates, and bridges all date back to the late 15th century, mostly attributed from 1467 to 1480. The end of the reconquesta in 1492 ended the immediate need for a large defensive fortification, and as such the castle's various reconstructions molded it into an administrative building. Later additions to the castle incorporate aspects of the Herrerian style of architecture. The current archive housed within the castle has been protected with fireproofing measures, and the 15th century chapel built by the Enríquez has been restored.References:
The city walls of Avila were built in the 11th century to protect the citizens from the Moors. They have been well maintained throughout the centuries and are now a major tourist attraction as well as a UNESCO World Heritage Site. Visitors can walk around about half of the length of the walls.
The layout of the city is an even quadrilateral with a perimeter of 2,516 m. Its walls, which consist in part of stones already used in earlier constructions, have an average thickness of 3 m. Access to the city is afforded by nine gates of different periods; twin 20 m high towers, linked by a semi-circular arch, flank the oldest ones, Puerta de San Vicente and Puerta del Alcázar.