Nearly 500 rivers lace Panama's rugged landscape. Mostly unnavigable, many originate as swift highland streams, meander in valleys, and form coastal deltas. However, the Río Chagres (''Chagres River''), located in central Panama, is one of the few wide rivers and a source of hydroelectric power. The central part of the river is dammed by the Gatun Dam and forms Gatun Lake, an artificial lake that constitutes part of the Panama Canal. The lake was created by the construction of the Gatun Dam across the Río Chagres between 1907 and 1913. Once created, Gatun Lake was the largest man-made lake in the world, and the dam was the largest earth dam. The river drains northwest into the Caribbean. The Kampia and Madden Lakes (also filled from the Río Chagres) provide hydroelectricity for the area of the former Canal Zone.