This picture shows Ligeia Mare, one of the ethane and/or methane "seas" on Titan. This picture was made from radar data from the Cassini spacecraft. The colors in the picture have been added. Blue areas are liquid ethane/methane, while brown areas are "dry land". This sea is near Titan's North Pole. It is slightly larger (in area) than Lake Superior on Earth.
Image courtesy of NASA/JPL/USGS.