The Borough of Castlereagh is situated to the south and east of the BMA.  It includes the urban areas of Dundonald, Gilnahirk, Braniel, Cregagh, and Newtownbreda, hereafter referred to as Metropolitan Castlereagh, together with the town of Carryduff, the village of Moneyreagh and the small settlements of Ballyknockan, Crossnacreevy and Ryan Park.   

Metropolitan Castlereagh is abutted to the north and the south by several areas of high landscape quality and to the south west by Lagan Valley Regional Park.  There are a number of landscape types including the good quality, rolling landform of large fields, bounded by hedgerows on the lower and upper Castlereagh slopes from the eastern fringe of Lisburn to Carryduff.  These extend into the prominent ridge of smooth rolling landform and steep gradient that forms the backdrop to Castlereagh and south east Belfast, stretching from Cairnshill in south east Belfast to the Comber Road in Dundonald.  Completing the landscape setting is Craigantlet Escarpment stretching from East Belfast to Holywood, relatively undeveloped, of an undulating landform with ample tree and hedgerow cover which has helped to integrate dwellings into the landscape. 

The population of the Borough in 2001 was 66,488, an increase of 9.4% from 1991.  In 2001 there were 30,244 people employed in the Borough. Of the total 82% were employed within the service sector, 11% in manufacturing and 5% in construction. The unemployment rate has fallen from 5% in 1991 to 2.9% in 2001. 

Major transportation routes into Belfast City Centre from the south and east run through the Borough and to a large extent the different parts of Metropolitan Castlereagh are connected by the outer ring road. 

Castlereagh Borough’s residential areas contain a range of housing types.  Commercial, community and leisure facilities and the Borough’s setting adjacent to the Holywood and Castlereagh hills make the area an attractive place to live.  Protection of the attractive setting of the Borough will retain the amenity of Castlereagh as a residential location.   

The Borough has an important employment role within the Metropolitan Area.  Restructuring of health provision at Purdysburn could unlock opportunities for employment generation, taking advantage of the sites distinctive parkland setting.

Castlereagh has major recreational facilities, including the outdoor leisure assets of Belvoir Forest Park, Lagan Valley Regional Park, and the Soccer Centre of Excellence, and indoors at Dundonald International Ice Bowl.

Retail development within the Borough is focused on Dundonald to the east, Forestside in Newtownbreda and within Carryduff Town Centre.