Ardglass (from Irish Ard Ghlais 'green height')[2] is a coastal fishing village, townland (of 321 acres) and civil parish in County Down, Northern Ireland, in the historic barony of Lecale Lower.

When the S.S. Great Britain was run aground in Dundrum Bay in 1846 due to a navigational error, Hughes was involved in her salvage.

This led him to champion Ardglass as a "Harbour of Refuge" for vessels off the northeast coast of Ireland in times of distress.

He invented and patented the keystone method of constructing sea walls in 1849-51 which involved stones being set together without the use of mortar to allow them to expand when being pounded by wave action.

Ardglass contains more medieval tower houses than any other town in Ireland, a total of four, reflecting its importance as Ulster's busiest port in the 15th century.

Francis Joseph Bigger, the Irish nationalist, and sometime Belfast solicitor, purchased Jordan's Castle at Ardglass in the 1890s.

of Downpatrick; and though now a mean village, with very few inhabitants, ranked, anciently, as the principal town of trade, next to Carrickfergus, in the province of Ulster.

it was a corporation, governed by a Portrieve.Ardglass has been a fishing port for more than two thousand years and developed as such due to its location on the east coast of Lecale and its sitting by a natural inlet.

Of these: On Census Day (27 March 2011) the usually resident population of Ardglass Settlement was 1,635 accounting for 0.09% of the NI total.