The Puente de Alcántara is a Roman arch bridge in Toledo, spanning the Tagus River. The word Alcántara comes from Arabic القنطرة (al-qanţarah), which means 'bridge'.
Located at the feet of the Castillo de San Servando, the bridge was originally built by the Romans after they founded the city. It was rebuilt by in the 9th and later in the 13th century by Alfonso X el Sabio. In the Middle Ages it was one of the few entrances of the pilgrim into the city.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.