Palencia Cathedral was built from 1172 to 1504 stands over a low vaulted Visigothic crypt (the Crypt of San Antolín). It is a large Gothic building, popularly dubbed as 'The unknown beauty' because not as well known as other Spanish cathedrals, though, it is a valuable building which has in its interior a large number of works of art of great value.
Its more than 130 metres long, 42 metres high and 50 metres wide at the centre, making it one of the largest cathedrals in Spain and Europe.
Its exterior solid, simple and austere does not reflect the grandeur of its interior, with more than twenty chapels of great artistic and historical interest. The most recognizable on the outside, is the tower, slim but a little rough, considering your Gothic style. Recent studies and excavations show that it was a military tower, and after serving this function were added to their pinnacles and cattail as the sole decoration.
The Cathedral's museum contains a number of important works of art, including a retablo of twelve panels by Juan de Flandes, court painter to Queen Isabella I of Castile and El Greco's St. Sebastian' (1576–79).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.