BEAUMARIS (formerly Bornovor, and deriving its present French name of Beau Marais from Edward I.), a borough and market-tow n of Anglesea, North Wales. It is situated on the Bay of Beaumaris, at the northern entrance of the Menai Straits, in lat. 53° 16' N., long. 4° 5' W. The town consists of several streets; and at the extremity of the principal one stands the castle. This fortress was built by Edward I. about 1295. It covers a great extent of ground, but its imposing effect is somewhat lessened by its low position, which was so designed that the fosse might communicate with the sea, so that vessels might unload beneath the walls. The chapel, dedicated to the Virgin, is a spacious structure, containing several fine monuments. A free school was founded here in 1GO3. The principal buildings are the town-hall, county hall, prison, custom-house, assembly-room, and national school. Beaumaris has no manufactures and comparatively little trade, but is much frequented as a bathing-place. It unites with Holyhead, Amlwch, and Llangefni in returning a member to parliament. The bay affords good anchorage, having seven fathoms of water at the lowest ebb. Population in 1871, 2291.