A lake as large as Wales and the largest in Europe, in the NW. of Russia, not far from St. Petersburg; it is the centre of an extensive lake and river system, receiving the Volkhov, Syas, and Svir, and drained into the Gulf of Finland by the Neva; but so dangerous is navigation, owing to sunken rocks and shoals and to the storms that prevail during the open months, that the extensive shipping is carried round the S. shores by the Ladoga and the canals.