Olbrück Castle is a hilltop fortress with a diamond-shaped floor plan. The central feature of the castle is the 34m high main tower, which dates back to the mid-14th century and is the oldest preserved part of the structure. Today, these rooms serve as museum spaces where visitors can learn about the construction history and function of castles. From the tower's roof, visitors have a panoramic view of the Rhine River to the east, the Ahr Mountains to the north, and the volcanic landscape to the south. On clear days, the Cologne Cathedral is even visible.
The castle was probably built originally in the 12th century. After several owners and reconstructions in the Late Middle Ages, During the Thirty Years' War, the castle was captured and devastated by Swedish troops in 1632. It was recaptured by Spanish and Electorate of Cologne troops under Graf Ernst von Isenburg-Grenzau in January 1633. Partially collapsed in 1660, the castle was subsequently restored under the supervision of Capuchin friar Bonitius from Linz.
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.