North Ronaldsay is the northernmost of the islands of Orkney and, with an area of, is the fourteenth largest. Mentioned in the Orkneyinga saga, in modern times it is known for its historic lighthouse, migratory bird life and unusual breed of sheep.GeographyNorth Ronaldsay lies around north of its nearest neighbour, Sanday at. The island is around long along its length and is defined by two large sandy bays; Linklet Bay on the eastern shoreline and South Bay at the south. The west of the island is very rocky with many skerries. Low-lying and exposed, the island's climate is extremely changeable and frequently inclement. The surrounding waters are stormy and treacherous, and have been a notorious "graveyard" for ships (hence the unusually early provision of a lighthouse on the island).Hollandstoun at the south of the island is the most sizable settlement lying roughly equidistant from the airfield and the pier. The island is also home to a bird observatory.North Ronaldsay has a unique dry stane dyke that surrounds the island whose purpose is to keep the seaweed-eating North Ronaldsay sheep off the arable land.HistoryA well-preserved Iron Age broch known as the Broch of Burrian is located on the southern tip of the island. Excavations in 1870-1 uncovered a large number of Iron Age and Pictish artefacts, with occupation continuing up to the Norse occupation of the Orkney islands in the 9th century.