The Pieterskerk (St. Peter's Church) is one of the oldest in Utrecht. Its construction began in 1039 and it was inaugurated on 1 May 1048 by Bernold, Bishop of Utrecht (although the lost west towers were probably only finished about a century after the inauguration). Characteristic of the Romanesque style in which it is built are the church's large nave pillars, each hewn from one piece of red sandstone, and the crypt under the choir. The building is now used by the Walloon Church.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.