Hornindalsvatnet is Norway's and Europe's deepest lake,[2] and the world's thirteenth deepest lake, officially measured to a depth of 514 m (1,686 ft). Its surface is 53 m (174 ft) above sea level, which means that its bottom is 461 m (1,512 ft) below sea level.
Its volume is estimated at 12 km3 (2.9 cu mi), its area is 51 km2 (20 sq mi) and ranks 19th in area among Norway's lakes. The main outflow is the river Eidselva, which flows into the Eidsfjorden, an arm off the main Nordfjorden.
The deepest point of the lake was explored using a ROV in 2006.[3] A small white fish was discovered on the lake bottom – probably a new species of Arctic charr (Salvelinus alpinus). It was previously also located in Lake Tinn, Norway's third deepest lake.[4]
The lake is also the site of the Hornindalsvatnet Marathon, held annually in July.[5]