Žeimenys

Lake Žeimenys (Lithuanian: alga) is a lake located in the district municipality of Švenčionys (it marks the administrative boundary between Vilnius and Utena counties) in northeastern Lithuania.

The lake is near Kaltanėnai, in the Aukštaitija National Park. The lake is very long and narrow, reminiscent of the shape of a river: as evidence of this, the size is 12 km in length, larger thus than any other lake in Lithuania, and 1.6 km in width (some consider it by this size to be on a par with a river). There are two busy bays for fishing in the northern part, bordering east and west. The maximum depth of the lake is 23.5 m. Coniferous forests surround it.

There are as many as 14 islands whose total area covers 8.3 hectares. The seabed is essentially composed of sand, gravel, and mud (the latter is present on 90% of the coastline). The coastal vegetation consists mainly of plants that are adapted to marshy climates. The transparency of the water in summer is such that visibility is guaranteed down to a depth of 3 m.

The main tributaries are the Laukupė, the Kretuona, and the Jaurupė, as an emissary figure of the Žeimenys In the northern part, a junction exists between the Žeimenys and Lake Šakarvai.