Ilmen is a historically important lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 in the Novgorod Oblast

Novgorod Oblast

Novgorod Oblast is a federal subject of Russia , located between Moscow and Saint Petersburg. Its administrative center is the city of Veliky Novgorod. Some of the oldest Russian cities, including Veliky Novgorod and Staraya Russa, are located there...

 of Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

, formerly a vital part of the Trade route from the Varangians to the Greeks

Trade route from the Varangians to the Greeks

The trade route from the Varangians to the Greeks was a trade route that connected Scandinavia, Kievan Rus' and the Byzantine Empire. The route allowed traders along the route to establish a direct prosperous trade with Byzantium, and prompted some of them to settle in the territories of...

. The city of Novgorod lies six kilometers below the lake's outflow.

Its average surface area is 982 km² (may vary from 733 to 2,090 km² depending on water level). The lake is fed by 52 inflowing rivers, the four main ones being Msta

Msta River

Msta is a river in Tver Oblast and Novgorod Oblast of Russia. Msta starts from the Mstino Lake in the Valdai Hills north of the town of Vyshny Volochyok and flows into Lake Ilmen. Up to mid-19th century, Msta had been a part of an important water trade route connecting the Baltic and Black seas...

, Pola

Pola River

Pola River is a river in Novgorod Oblast of Russia. It begins in the north-west of Valdai Hills, and flows into the Lake Ilmen, joining the Lovat River downstream....

, Lovat

Lovat River

The Lovat River is a river in Belarus and Russia. It flows out of Lovatets Lake in northwestern Belarus, and flows north through Pskov and Novgorod Oblasts of Russia into Lake Ilmen. Its main tributaries are the Kunya, Polist, Redya, and Robya Rivers....

, Shelon

Shelon River

Shelon River is a river in the northwest part of European Russia, one of the main tributaries of Lake Ilmen. It has a length of 248 km and drains a basin of 9710 km².The river flows through the Novgorod Oblast and the Pskov Oblast.- History :...

 and is drained through a single outlet, the Volkhov

Volkhov River

Volkhov is a river in Novgorod Oblast and Leningrad Oblast in northwestern Russia.-Geography:The Volkhov flows out of Lake Ilmen north into Lake Ladoga, the largest lake of Europe. It is the second largest tributary of Lake Ladoga. It is navigable over its whole length. Discharge is highly...

, into the Lake Ladoga

Lake Ladoga

Lake Ladoga is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, not far from Saint Petersburg. It is the largest lake in Europe, and the 14th largest lake by area in the world.-Geography:...

, and subsequently via the Neva

Neva River

The Neva is a river in northwestern Russia flowing from Lake Ladoga through the western part of Leningrad Oblast to the Neva Bay of the Gulf of Finland. Despite its modest length , it is the third largest river in Europe in terms of average discharge .The Neva is the only river flowing from Lake...

 into the Gulf of Finland

Gulf of Finland

The Gulf of Finland is the easternmost arm of the Baltic Sea. It extends between Finland and Estonia all the way to Saint Petersburg in Russia, where the river Neva drains into it. Other major cities around the gulf include Helsinki and Tallinn...

.

The water level is regulated by the Volkhov hydroelectric plant

Volkhov hydroelectric plant

Volkhov hydroelectric plant , named after V.I. Lenin, is a hydroelectric station on the Volkhov River located in the town of Volkhov, Leningrad Oblast, in northwestern Russia. It is the oldest and longest serving hydroelectric plant in Soviet Union and Russia. It is a part of the Ladoga...

 situated downstream the Volkhov River. Water temperature in July is 19-20°C. Bathing season is about 90 days. Fishery. Shipping lines are Novgorod – Staraya Russa

Staraya Russa

Staraya Russa is a town in Novgorod Oblast, Russia, located south of Veliky Novgorod. It is a wharf on the Polist River in the Lake Ilmen basin. It serves as the administrative center of Starorussky District, although administratively it is not a part of it...

 and Novgorod – Shimsk

Shimsk

Shimsk is an urban locality and the administrative center of Shimsky District of Novgorod Oblast, Russia, located on a highway connecting Veliky Novgorod and Pskov, southwest of Veliky Novgorod. Another road connects the settlement with Staraya Russa. Shimsk lies on Shelon River, approximately ...

.

The lake area was the location of an important battle during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, the Demyansk Pocket

Demyansk Pocket

The Demyansk Pocket was the name given for the encirclement of German troops by the Red Army around Demyansk , south of Leningrad, during World War II on the Eastern Front. The pocket existed mainly from 8 February-21 April 1942. A much smaller pocket was simultaneously surrounded in Kholm, about ...

.

Trivia

• Folk Metal band Turisas
  Turisas
  Turisas is a Finnish folk metal band from Hämeenlinna. It was founded in 1997 by Mathias Nygård and Jussi Wickström and named after an ancient Finnish God of war....
  
  makes a reference Lake Ilmen in their song "A Portage to the Unknown".