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 of Hafnarfjörður has 5 rods in Hlíðarvatn and a good fishing house. In May, June and July, individual rods are sold, but in August and September, all rods are sold together.