Lake Langavatn is in Reykjahverfi between Mývatn and Húsavík. It is 158 m above sea level and its measured area is 0.6 km². The lake has both brown trout and Arctic char. Most of the char are small and the lake is overcrowded, and it would help to do some considerable net fishing. Langavatn is a part of the water system of Laxá in Aðaldal. From the lake, river Mýrarkvísl flows down to river Laxá and from there to the sea. Geitafellsá flows into the lake, but it originates in Kringluvatn. There is often good fishing in the middle of the lake, from the west bank, and where the Geitafellsá river flows into it. The lake also has good ice fishing and Iceland Fishing Guide offers ice fishing tours to the lake.