Ring-Shaped Manicouagan Reservoir and Île René-Levasseur, Canada51.3N 68.6W
The distinct, white ring in the center of this image is actually a frozen lake, the Manicouagan Reservoir. The 1942 km2 reservoir, located at an elevation of 360 m, is in southeastern Quebec, about 140 km from the Labrador border.
The unusual anular shape is due to the fact that a partially eroded meteorite impact crater was filled with water. The reservoir contains a centrally situated island, Île René-Levasseur, capped by 952 m high Mont de Babel.