Slieve Donard, highest peak (2,796 feet [852 metres]) in the Mourne Mountains at the border of Down district and Newry and Mourne district, N.Ire. It is near the coast at the northeastern end of the Mournes. Intensive glacial and periglacial action has produced bare crags, peaks, and rock debris on the lower slopes. There are some remains of an oratory erected on the summit in the 5th century by St. Domhangort (Donard), after whom the mountain is named.