Lake Purkuvatn has an area of 0,28 km². It is shallow and situated 231 m above sea level. Its discharge, Purkulaekur, flows through the valley Svinadalur and spills into the bay Vopnafjordur.
A passable road for most vehicles lies all the way to the lake. The lake char is said to be quite big and tasty. There are many more lakes in the so-called Sandvikurheidi area and many of them near the main road (Hundsvatn, Midheidarvatn).
The distance from the capital is 640 km by the Whale Bay tunnel and 14 from Vopnafjordur.