Loch Ness ( /ˌlɒx ˈnɛs/; Scottish Gaelic: Loch Nis, [l̪ˠɔxˈniʃ]) is a large, deep, freshwater loch in the Scottish Highlands (57°18′N 4°27′W / 57.3°N 4.45°W / 57.3; -4.45) extending for approximately 37 km (23 mi) southwest of Inverness. Its surface is 15.8 m (52 ft) above sea level. Loch Ness is best known for the alleged sightings of the cryptozoological Loch Ness Monster, also known affectionately as "Nessie". It is connected at the southern end by the River Oich and a section of the Caledonian Canal to Loch Oich. At the northern end there is the Bona Narrows which opens out into Loch Dochfour, which feeds the River Ness and a further section of canal to Inverness. It is one of a series of interconnected, murky bodies of water in Scotland; its water visibility is exceptionally low due to a high peat content in the surrounding soil.