Grafarvatn is one of three lakes in Eiðaþinghá that lie north of Eiði and the abandoned farm Gröf. The others are Arnarvatn and Mjóavatn and they are usually called by one name, Grafarvötn. Grafarvatn, which is 30 m above sea level and about 0.43 km² in area, is the westernmost of them and closest to Lagarfljót. In here, as with the other lakes, there are mainly brown trout, but also Arctic char and fish have been caught up to 3-4 pounds. Fishing rights in Grafarvatn, and also Mjóavatn, belong to the farms Gröf and Eiði. Gröf is owned by the municipality of Fljótsdalshérað, which therefore owns the fishing rights in the lakes. Fishing is not allowed in Lake Arnarvatn. It is a short walk to Grafarvatn from the deserted farm Gröf, but it is best to get to Mjóavatn from a trail that is by highway 94.