Wikipedia
Castlereagh was a local government district with the status of borough in Northern Ireland. It merged with Lisburn City Council in May 2015 under local government reorganisation in Northern Ireland to become Lisburn and Castlereagh City Council, with a small amount being transferred to Belfast City Council.
It was a mainly urban borough consisting mostly of suburbs of Belfast in the Castlereagh Hills (to the south-east of the city) with a small rural area in the south of the borough. Unusually, it had no natural borough centre. The main centres of population are Carryduff, 6 miles (9.6 km) south of Belfast city centre and Dundonald, 5 miles (8 km) east of it.
Castlereagh was named after the barony of Castlereagh, which in turn was named after the townland of same name.
Castlereagh may refer to:
Castlereagh is a townland and former hamlet in the civil parish of Knockbreda, barony of Castlereagh Lower, in County Down, Northern Ireland. It is southeast of Belfast and now at the fringe of the city's suburbs. The townland has an area of .
Castlereagh is the name of a former barony in County Down, present-day Northern Ireland. It spanned the north-eastern area of the county bordering the baronies of: Ards to the east; Belfast to the north; Iveagh to the west south; and Dufferin, Kinelarty, and Lecale to the south. By 1841 the barony was divided into Castlereagh Lower and Castlereagh Upper.
Castlereagh is a barony in County Roscommon, Ireland. It is named after the town of Castlerea within the barony. Its area in 1891 was .
It contains five civil parishes: Ballintober, Baslick, Kilkeevin, Kilcorkey, and Kiltullagh; including the towns of Ballinlough, Bellanagare, Castlerea, and Cloonfad.