Great Captain Island, also known more familiarly as "Great Captain's Island," is an island off the coast of Greenwich, Connecticut. The 17.2-acre (70,000 m²) island is the largest of a three-island group that also includes Little Captain and Wee Captain. The island is a remnant of a glacial moraine and has a large glacial erratic on the southern side, the island's east and west sides are connected by a tombolo. The island has had several owners, but has been owned in whole by the Town of Greenwich since 1973. The island is home to the Great Captain Island Light, a 19th-century lighthouse that was restored in 2009 and relit as a non-navigational aid in 2012. The actual navigation aid is a skeletal tower erected in 1970. Great Captain Island is one of the state's 26 "important bird areas" according to the Connecticut Audubon Society. The town operates a ferry service to and from the island from about the second week in June through the second week of September. Trails have been laid out for visitors, and the western part of the island has picnic tables, grills, restrooms, and posted swimming areas. The island is open year round, with a ferry running during the summer.