ACHILL, the largest island off Ireland, separated from the Curraun peninsula of the west coast by the narrow Achill sound. Pop. (1926) 5,008. It is included in Mayo. Its shape is triangular, and is 15m. from east to west and from north to south. Area 57sq.m. The island is mountainous, the highest points being Slieve Croaghaun (2,192ft.) in the west, and Slievemore (2,2o4f t.) in the north ; the extreme western point is the bold and rugged promon tory of Achill head, and the north-western and south-western coasts consist of cliffs reaching 800ft. in Minaun, near Keel on the south. The seaward slope of Croaghaun is abrupt and the scenery beautiful. Desolate bogs alternate with the mountains; and the inhabitants earn a scanty subsistence by fishing and tillage, or go to England and Scotland during the harvesting. The Con gested Districts Board has made efforts to improve the condition of the people, and a branch of the Great Southern railway to Achill sound, together with a swivel bridge across the sound, improved communications. In Dugort is a Protestant colony, known as "the Settlement," founded in 1834. There are megalithic remains at Slievemore and elsewhere.