Jääsjärvi (; ) is a medium-sized

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

. It is located in the Hartola and

Joutsa Joutsa is a municipalities of Finland, municipality of Finland. It is located in the provinces of Finland, province of Western Finland and is part of the Central Finland regions of Finland, region. Jyväskylä is located about north of the Jouts ...

municipalities A municipality is usually a single administrative division having municipal corporation, corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate. The term ''municipality' ...

, in the

Central Finland Central Finland (; ) is a Regions of Finland, region ( / ) in Finland. It borders the regions of Päijät-Häme, Pirkanmaa, South Ostrobothnia, Central Ostrobothnia, North Ostrobothnia, Northern Savonia, North Savo, and Southern Savonia, South S ...

and Päijänne Tavastia regions. The water quality in the lake is excellent.Jääsjärvi
Järviwiki Web Service. Retrieved 2014-02-28. The

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

Tainionvirta The Tainionvirta is a river in the Päijät-Häme region of Finland. It begins at Jääsjärvi, Hartola. At Sysmä the river flows into the Päijänne. Its length is , and it drops about . There are five rapids, but typically water flows quit ...

has its source in Jääsjärvi and flows through several smaller lakes to Päijänne. The water in Jääsjärvi is bright. The lake is part of the Sysmä catchment area and

Kymijoki The Kymi (, ) is a river in Finland. It begins at Lake Päijänne, flows through the provinces of Päijänne Tavastia, Uusimaa and Kymenlaakso, and discharges into the Gulf of Finland. The river passes the towns of Heinola and Kouvola. The to ...

main

catchment area A catchment area in human geography, is the area from which a location, such as a city, service or institution, attracts a population that uses its services and economic opportunities. Catchment areas may be defined based on from where people are ...

. There are dozens of

islands This is a list of the lists of islands in the world grouped by country, by continent, by body of water, and by other classifications. For rank-order lists, see the #Other lists of islands, other lists of islands below. Lists of islands by count ...

in the lake. The biggest are Vehkasalo, Hirtesalo, Kotisalo, Ohrasaari, Urrionsaari, and Nautsalo. Vehkasalo, Hirtesalo, and Ohrasaari have roads connecting them to the mainland. In winter time, the lake typically freezes.

References

See also