There is a legend that this river was turned back by the hero Ilya Muromets. Previously, it flowed to the Volga - to the south, and now to Ilmen - to the north. The total length of the meandering river is 87 kilometers. The source of Yavan was blocked in 1944 by a dam at the drain from Lake Veljo. As a result, the upper reaches of the river, in fact, are an independent river, the source of which is located in Lake Bolshoye Yaichko, Demyansk district of the Novgorod region, and its mouth in Lake Veljo.