the capital of the Isle of Man, and seat of the Manx government, stands on the western side of Castletown bay, 11 miles S.W. of Douglas. It is a neat and regularly built town, and has a large square containing some handsome houses. Castle-Rushen, said to have been built about 960 by the Danish chief Guttrud, and afterwards the residence of the kings of Man, stands in the centre of the town, and is now partly used as a prison and barracks. Castletown has a church, three chapels, market-house, college, bank, and literary society. Pop. 2579.