, seen from Ladakalnis Hill The great majority of Lithuania's lakes formed after the
Wisconsin glacier retreated. The oldest date from about 13,000 years before the present. The varieties of
glacial lakes include: •
Moraine-dammed lakes (Lithuanian:
užtvenktiniai ežerai) formed when glacial
moraines blocked glacier meltwater drainage. These lakes include Dysnai, Plateliai, and
Vištytis •
Kettle lakes (Lithuanian:
guoliniai or
termokarstiniai ežerai) formed when a large piece of ice broke away from the edge of a retreating glacier, and was then buried under its
sediments. After the piece melted, a small depression was left in the landscape that filled with water. These lakes tend to be small, round, and quite deep. Due to their small size most of them are unnamed. The best-known of these is Lake Druskonis. • (Lithuanian:
Ledo guolio ežerai) formed much like kettle lakes, but are much larger. The pieces of ice were not buried under sediment. These lakes are often irregularly shaped, with uneven bottoms. Examples include Dusia, Metelys, Obelija, and
Kretuonas. • (Lithuanian:
Dubakloniai, latakiniai, or
rininiai ežerai) formed when meltwater washed steep, narrow, and deep valleys. When the valleys filled with water afterwards, lakes such as
Asveja, Tauragnas, Sartai, and Aisetas were formed. • Residual lakes (Lithuanian:
liekaniniai ežerai) are the remains of large lakes that formed immediately adjacent to melting ice caps. These lakes are large, shallow, and surrounded by
wetlands and
peat bogs. Examples include Rėkyva, Žuvintas, and Amalvas. • Some lakes are of mixed origins, created when a dam was constructed and the resulting reservoir flooded one or more lakes of glacial origin. Examples include
Drūkšiai, Didžiulis or Daugai, and Galvė. The lakes of non-glacial origins include: •
Oxbow lakes (Lithuanian:
senvaginiai, salpiniai, or
upiniai ežerai) are abundant. There are over 1,300 of them. The largest are located in the
Neman River delta. •
Sinkhole lakes (Lithuanian:
karstiniai ežerai) are prevalent in the
Biržai district municipality. There are about 300 such lakes, although their surface area covers only 10
hectares. It has been suggested that most of them are interconnected. • Underground lakes (Lithuanian:
požeminiai ežerai) are also found in the Biržai district municipality. The largest one is in Cow's Cave (Lithuanian:
Karvės ola); its water temperature is a constant +4.5 degrees Celsius. • A marine lake (Lithuanian:
lagūniniai or
jūriniai ežerai),
Krokų Lanka, was formed when various drifts from the
Neman River separated a part of the
Curonian Lagoon. It is the only such lake in Lithuania. • Reservoirs (Lithuanian:
tvenkiniai or
kūdros) were created when a river was dammed, or were excavated as a local project. There about 3,400 such lakes, but only 340 of them cover more than 5 hectares. Most of the dams were built during the second part of the 20th century when the
Soviet government authorities organized massive land use changes. ==Largest lakes==