Loch Ness, the most famous Loch in the world, extends from Fort Augustus in the South to the narrows of Bona Ferry in the north, a distance of almost 23 miles. The waters of Loch Ness cover an area of almost 22 square miles and at it's deepest has a depth of 754 feet. The most surprising statistic is the volume of water contained in the Loch which is estimated to be 263 000 million cubic feet. This exceeds that of any other Loch or lake in Great Britain and is three times greater than Loch Lomond. Loch Ness is famed throughout the world for its monster, Nessie. There have been numerous sightings over many years and the usual description of the monster is a small head at the end of a long neck, with a broad body with humps. Nessie is also described as having four flippers and a long tail with a rounded end. Castle Urquhart (pronounced "urkhurt") stands on a rocky promontary on the north shore of Loch Ness. At nearby Corrimony is a burial cairn dating from about 2000 BC. However, although some evidence has been found of a fort on this promontory dating from the Iron Age, and also remains from Pictish times, earliest written records for the existence of a castle date from the 1200's. Loch Ness cuts a great divide along what is called Glen Mor, or The Great Glen, a 60 mile fissure scoured by glaciers during the last ice age. The Loch itself is over 700 feet deep, and the nearby surrounding hills rise by about the same amount. At the north east end, where the waters of the loch flow along the River Ness through Inverness and into the North Sea, is the flatter and more fertile land of Moray.