Lake Washington is a large freshwater lake adjacent to the city of Seattle, Washington, United States. It is the largest lake in King County and the second largest natural lake in the state of Washington, after Lake Chelan. It borders the cities of Seattle on the west, Bellevue and Kirkland on the east, Renton on the south, and Kenmore on the north, and encloses Mercer Island. The lake is fed by the Sammamish River at its north end and the Cedar River at its south.