Lake Waccamaw is a fresh water lake located in Columbus County in North Carolina. It is the largest of the natural Carolina Bay lakes. Although bay trees are present within many Carolina Bays, the term "bay" does not refer to the trees but comes instead from an early science publication by Glenn (1895), who used the word "bay" to refer to these features near the town of Darlington, South Carolina. Lake Waccamaw is fed by four creeks: First, Second, Third, and Big creeks. The outlet forms the Waccamaw River which flows south-southwest to empty into the Atlantic Ocean near Georgetown, South Carolina

Carolina bays are elliptical to circular depressions concentrated along the East Coast of the United States within coastal New York, New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, and north Florida. In Maryland, they are called Maryland basins. Within the Delmarva Peninsula, they and other coastal ponds are also called Delmarva bays.