Loch Ness is a large, deep freshwater lake (known in Scotland as a loch; in Ireland, the spelling is "lough") in the Scottish Highlands, extending for about 40 miles to the south-west of Inverness. It is the largest body of water in a large valley known as the Great Glen, which runs from Inverness in the north to Fort William in the south. The Caledonian Canal, which links the sea at either end of the Great Glen, uses Loch Ness for part of its route.
Loch Ness is perhaps best known for the sightings of the fabled monster, "Nessie", the Loch Ness monster, although it is scenic in its own right. Boat cruises operate from various locations along its shores giving tourists the chance to look for the monster.
It also acts as the lower storage reservoir for the Foyers pumped-storage hydroelectric scheme, which was the first of its kind in Britain. The turbines were originally used to provide power for a nearby mill, but now electricity is generated and supplied to the National Grid.
At its southwestern end, near Fort Augustus, several Crannogs (artificial islands generally from the Iron Age) have been created or improvised on a shallow shelf.