Rathfriland Castle Rathfriland Castle ( ) is a ruined castle at Rathfriland , County Down , Northern Ireland . The castle was a square building of 3 – 4 storeys with a stone barrel vault at the first floor level to reduce the risk of fire and was one of the seats of the Magennis ' s , Lords of Iveagh . Most of it was pulled down by Mr . William Hawkins of London , after the rebellion of 1641 , and the remainder destroyed by General Henry Ireton on Oliver Cromwell ' s orders . History . Rathfriland Castle is believed to have been erected in the 15th or 16th century which would have replaced earlier wooden structures . The original building is estimated to have been 30 feet by 50 feet and would also have had a stone perimeter wall . The stone was quarried from the hill itself and created a steep precipice on the west side which would have been useful in defending the site . The steepness of the site can still be appreciated when approaching the town from the Banbridge direction . The Magennis clan were overlords of the territory of Iveagh from 1136 . Arthur Magennis , first Viscount Iveagh , was married to Lady Sarah O ' Neill the daughter of Hugh O ' Neill , Earl of Tyrone , who led the Gaelic clans in the nine years ' war against the English . He remained on after the ` Flight of the Earls ' and the Plantation of Ulster . He died in 1629 and was buried with his ancestors in Drumballyroney Churchyard which is approximately a mile north of the town . ( The church and cemetery are in the Roman Catholic parish of Annaclone . They are now part of the Bronte Homeland Museum ) . Lady Sarah lived after his death in their castle at Narrow Water , Warrenpoint . His son , Hugh Magennis , was the last of the family to hold Iveagh . His role in the 1641 rebellion brought about their final downfall and loss of the family lands . Destruction . Following the defeat of the 1641 rebellion , the castle was destroyed by Cromwell ' s General Ireton and the manor of Rathfriland was granted to Alderman William Hawkins . His son , John Hawkins finally pulled down most of the castle and built a new manor house in the townland of Lessize below the town . No trace of this now remains . John Hawkins married Mary Johnston of Gilford through whom the family inherited the Gilford estate . He died in 1689 and was also buried at Drumballyroney along with the Magennises . The manor passed down to his great - granddaughter , Theodosia Hawkins Magill , who married Sir John Meade , later Earl of Clanwilliam . She was an independent woman for her time and managed these lands by herself leaving them , on her death , to her second son . The family lived mostly in Norfolk but had a Georgian Cottage at Burrenwood , near Castlewellan , which was built by Theodosia Hawkins Magill . Existing structure . All that remains standing today of Rathfriland Castle is a small portion of the south gable wall . measuring 30 feet long by 25 feet wide . When it was finally taken down by John Hawkins , the stones were said to have been used to build some of the oldest buildings of the town . Among those which have survived is the old three - storey ` Town Inn ' which still stands at the corner of The Square and Newry Street . The cellar of this building was said to be the meeting place of the notorious ` Hellfire Club ' in the 18th century .