Lake Ilmen

Lake Ilmen is a large lake in the Novgorod Oblast of Russia. A historically important lake, it formed a vital part of the medieval trade route from the Varangians to the Greeks. The city of Novgorod - which is a major trade-center of the route - lies six kilometers below the lake's outflow.

According to the Max Vasmer's Etymological Dictionary, the name of the lake originates from the Finnic Ilmajärvi, which means "air lake". Thanks to Novgorodian colonisation, many lakes in Russia have names deriving from Lake Ilmen. Yuri Otkupshchikov has argued that the presence of the name "Ilmen" in Southern Russia can't be explained by the Novgorodian colonisation alone, and proposed a Slavic etymology instead.The average surface area is 982 square kilometres.

Source: Wikipedia