Lake Langavatn is the largest lake between town Skagaströnd and the farm Hof in the western part of the peninsula Skagi.  It has an area of 3,5 km² and is situated 207 m above sea level.  River Fjallabaksá enters it from the south and its discharge, Langavatnsá, connects it with lake Skjaldbreiðarvatn.

The lowest part of the discharge is called Fossá, which cascades over the cliff Króksbjarg into the sea.  The lake is accessible by car (or over 5 km on foot).  The lake abounds in lake char and brown trout, mostly 1-3 pounders.  There is no limit to permits sold per day for Lake Langavatn.  The farmers net both lakes.  Lake Skjaldbreiðarvatn has an area of 0,3 km².

Drive to the lake passable by 4wd vehicles from farm Steinnsýrastodum.

The distance from the capital is 282 km by the Whale Bay tunnel and 15 from Skagastrond.