Híðarvatn in Selvogur has for years been one of the most productive Arctic char lakes in the country. Its maximum depth is about 5 meters, and its size is just over 3.3 km². Its drainage is through Vogsós, but the lake comes up from the lava through countless springs. Hlíðarvatn is a very exciting fishing lake and thousands of char are caught there every summer. This is a fish that is considered very delicious and fun to eat. Most of the fish are 0.5-1 pounds, but every summer a few 5-pound fish and even bigger ones are caught. In addition to sea char, occasional salmon have been caught in the lake.
The Angling club Selfoss has had fishing rights in the lake since 1978. Two rods are allowed and are sold together.