The ruined castle Burg Drachenfels, on the summit of the Dhill, was built between 1138 and 1167 by Archbishop Arnold I of Cologne and bears the same name. It was originally intended for the protection of the Cologne region from any assault from the south. Originally it consisted of a bergfried with court, chapel and living quarters for servants. The castle was slighted in 1634, during the Thirty Years' War, by the Protestant Swedes and never rebuilt. As a strategic asset it had outlived its usefulness. Erosion due to the continued quarrying undermined much of the remains and only a small part is left today.
References:The Broch of Clickimin is a large and well preserved, though somewhat restored broch near Lerwick. Originally built on an island in Clickimin Loch (now increased in size by silting and drainage), it was approached by a stone causeway. The water-level in the loch was reduced in 1874, leaving the broch high and dry. The broch is situated within a walled enclosure and, unusually for brochs, features a large 'blockhouse' between the opening in the enclosure and the broch itself. Another unusual feature is a stone slab featuring sculptured footprints, located in the causeway which approached the site. Situated across the loch is the Clickimin Leisure Centre.