Charleston Light on Sullivan's Island, South Carolina, which is the northern entrance to Charleston Harbor, was built to replace the defunct Morris Island Light on Morris Island. Construction was started in 1960, and it was first lit on June 15, 1962. The lighthouse has a steel frame, an aluminum alloy skin, and a modern triangular cross section. It is 140 ft (42.7 m) tall. The focal plane of the light is 163 ft (49.7 m) above mean sea level.