ACHILLBEG, an Island, in the parish of Achill, union of West-port, barony of Burrishoole, county of
Mayo, and province of Con naught, 22 miles (W.) from Newport-Mayo ; containing 178 inhabitants. This
island is situated on the western coast, and on the north side of the entrance of Clew bay ; it is separated
from the larger island of Achill by a narrow sound, which in some parts is fordable and almost dry at low
water. The western shore is very wild, and, in consequence of the swells running to a great height, is unapproachable even in the calmest weather: the highest point is 360 feet above the level of the sea. The isle comprises 330 1/2 statute acres, the property of Sir Richard A. O’Donnell, Bart. . a small portion of the
land is arable, and the remainder is rocky pasture. A coast-guard station has been established here, and placed under the superintendence of an inspecting chief officer, resident at Dugort, in the island of Achill.
Extract from: Lewis – A Topographical Dictionary of Ireland