Lake Urdarhaedarvatn lies just a stone’s throw away from The lake Ulfsvatn towards northwest. It has an area of 2,3 km². It is shallow and located at 447 m above sea level. Its discharge feeds Lake Kvislarvatn nyrdra. The lake char and brown trout of the lake are large enough and well tasting. A 4wd track lies all the way to the lake.
The distance from the capital over the mountain pass Kaldidalur is about 200 km.