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.
Ármenn is one of the companies that leases fishing rights in Hlíðarvatn. The company was founded on 28 February 1973 and rents out 3 rods in the lake together with a fishing house/cabin, Hlíðarseli.