lie to the northeast and northwest. For the purposes of the Office for National Statistics, Radcliffe forms a northerly part of the Greater Manchester Urban Area, with Manchester city centre to the south-southeast. Radcliffe's position on the River Irwell has proved important in its history and development as the river provided a source of water for local industry. Radcliffe E'es, a level plain formed along the north bank of the Irwell during the previous ice age, is now derelict and the planned location of a new school. From a highpoint of above sea level in the northwest of Radcliffe, the surface gradually descends, particularly in the south and east, being the lowest along the River Irwell. The geology is represented by coal measure. Radcliffe is surrounded by open space and rural land, much of which is visible from the town centre. To the east of the town the River Roch flows under Blackford Bridge, and joins the Irwell shortly thereafter, along which several weirs and goits were built as it passes through the town. Flowing from east to west the river divides the town on the north and south sides of the valley respectively. The town centre sits on the north side of the valley. Two road bridges cross the river: one in the former hamlet of Radcliffe Bridge, and another newer bridge built as part of the A665 Pilkington Bypass. Another bridge crosses the river along the eastern border with Bury. Various smaller pedestrian footbridges and two railway viaducts (one disused) also exist. Demography According to the Office for National Statistics, at the time of the United Kingdom Census 2001, Radcliffe had a population of 34,239. The population density in 2001 was , with a 100 to 94.9 female–male ratio. Of those over 16 years old, 28.6% were single (never married) and 42.8% married. Radcliffe's 14,036 households included 28.1% one-person, 39.0% married couples living together, 9.2% were co-habiting couples, and 12.3% single parents with their children. The figures for married couples households was below the borough (48.5%) and national average (47.3%), and single parent households were slightly above the average for the whole of Bury (11.6%) and England (10.5%). Of those aged 16–74, 31.1% had no academic qualifications, slightly higher than averages of Bury (29.2%) and England (28.9%). The residential areas of Radcliffe both to the north and the south of the town centre operate as suburbs of Bury