DONAGHADEE, a market town of Ireland, in county Down, situated near the mouth of Belfast Lough on the Irish channel, is the nearest port in Ireland to Great Britain, being 21⅜ miles S.W. of Port Patrick in Wigtownshire. It consists of two principal streets, and possesses a harbour which admits vessels of 16 feet in draught. On the north-east side of the town there is a rath 70 feet high, in which a powder magazine has been built. The town is frequented for sea-bathing in the summer months. Population (1871), 2226.