This mysterious creature is said to inhabit the depths of Scotland's Loch Ness, a large, deep freshwater lake. Sightings of the creature, affectionately known as Nessie, have been reported since the 6th century, but the most famous sighting occurred in 1933. The Loch Ness Monster
From Wikipedia
The Loch Ness Monster, known affectionately as Nessie, is a mythical creature in Scottish folklore that is said to inhabit Loch Ness in the Scottish Highlands. It is often described as large, long-necked, and with one or more humps protruding from the water. Popular interest and belief in the creature has varied since it was brought to worldwide attention in 1933. Evidence of its existence is anecdotal, with a number of disputed photographs and sonar readings.