The oldest building in the Dundee is St Mary's Tower, which dates from the late 15th century. This forms part of the City Churches, which consist of St Clement's Church, dating to 1787–88 and built by Samuel Bell, Old St Paul's and St David's Church, built in 1841–42 by William Burn, and St Mary's Church, rebuilt in 1843–44, also by Burn, following a fire.
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.