The Cathedral Basilica of the Holy Cross (Bazylika Katedralna Podwyższenia Krzyża Świętego) was built in the 15th century on the site where before there was a structure of the 11th and 13th centuries. It was rebuilt several times. With towers with a height of 73 meters is the tallest structure in the city. In the temple there is a painting of the Virgin of Opole, brought there permanently in 1702.
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.