Castletown, Isle of Man House of Keys moved from Castletown to Douglas. The Isle of Man Census 2011 lists the town's population as 3,097 (2006: 3,109) It is the fourth largest town on the island, after Douglas, Ramsey and Peel, but is also smaller than Onchan and Port Erin, which have the status of villages. The town lies on the northwest side of Castletown Bay. The opposite shore of the bay is the west coast of the distinctively-shaped Langness Peninsula. To the north-east are Ronaldsway Airport and industrial zone, and the village of Ballasalla; to the north-west the villages of Ballabeg and Colby; and
Castletown, Dorset is found in the village, close to the entrance of Portland Port. The area still features several hotels and pubs, largely established for the navy personnel that once came from the port. The Osprey Leisure Centre is located in Castletown, which was formerly known as the Boscawen Centre, and was opened to the public in May 2007. Originally it was a private Royal Navy facility during the 1980s. Castletown also holds the Portland Community Hospital. This was originally a Royal Naval Hospital which served Portland's naval base from the late 19th century until 1957, when the hospital was handed over