Onega, a lake in Russia, lying to the north-east of Ladoga, has an area of 3,764 square miles. The river Swir flows from it into Lake Ladoga, and many streams enter it. It is very deep in some places, and is covered with ice for more than a third of the year. Onega is full of fish, and is the scene of a busy trade. A canal has recently been made connecting it with the White Sea.