Culswick Broch is an unexcavated coastal broch, an Iron Age drystone hollow-walled structure. Built of striking red stone, it has beautiful views all around, including Foula and Vaila isles, and Fitful Head and Fair Isle in the south. The broch stands commandingly on the top of a massive rock platform and is about 3 metres high at its tallest point. Much rubble has fallen into the centre. This broch has a massive triangular lintel stone over the entrance, which is partly filled with rubble.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.