The Casements was the winter retreat of John D. Rockefeller, the Standard Oil founder and, for much of his life, the wealthiest man in the world. He acquired the riverside cottage in 1918 and wintered here regularly until his death in 1937 at the age of 97. The house takes its name from its casement windows — a distinctive architectural feature that gives the building its character from the street.
Today The Casements operates as a cultural centre and local history museum, listed on the National Register of Historic Places. The rooms retain period furnishings and are used for meetings, exhibitions, and events. The grounds include a riverfront garden reconstructed in the style of Rockefeller's day, with palms, manicured hedges, and views across the Halifax River. Tours run on weekday mornings; admission is free but donations are welcomed. The museum is on Granada Boulevard, the main street linking the mainland to the beach barrier island.