Manannan House, on Market Square, began life in the late eighteenth century as a public house known as The George, owned by John Murray, 4th Duke of Atholl. The War Office acquired the building in 1828 and converted it into barracks around 1830, and it served as a garrison until the troops were withdrawn in 1896. In 1911 the War Department sold the property to the Castletown Commissioners for £600, and it became the town's Town Hall, remaining so until a new civic centre was built in 1989, after which the building passed into private ownership and was renamed Manannan House. Today it houses retail and leisure tenants on Castletown's main square.