54°11′13″N 6°22′41″W / 54.187°N 6.378°W Derrymore House (Irish: Teach Dhoire Mhóir) is a National Trust property in Bessbrook, County Armagh, Northern Ireland. The grounds are open to the public most of the year round and the drawing room or "Treaty Room" in the house itself on selected dates only. It is described by the National Trust as a "late 18th-century thatched house in gentrified vernacular style".[1]