The lake is in Zarasai and Rokiskis districts in Sartai Regional Park. It is the fifth largest lake in Lithuania, which is highly branched, narrow, valley origin (6 intersect rinos) complex configuration. The banks are up to 30 m. Sartai area - 1,350 ha, the deepest place - 22 m, the average depth - 5,72 m, the winding coastline - 80 km. Dominated by the bottom of the sludge, only on the edges of the shallows and the tributaries of the mouth are sandy sediments. The most comfortable in this lake to fish from a boat. Full of fishes lake is plenty of wild bleak, perch, bream, roach, crucian carp, pike, tench, ide, bream, ruff, red and chub, and without the usual fish species occur in the pike-perch, on the lake planted owlies, whitefish, living in Europe, rare and protected species - catfish and bitterling. Fishermen of Dusetos region have a lot to be proud of. Here are just a few of the catch: in 1951 in Kriaunai winter anglers caught a 38 kg catfish, in 1956 in Dusetos fishermen hauled caught pike weighing 45 kg, and  in 1981 even amateur fisherman caught a 51 kg catfish, which was devoured two duck.