 Oldham 's built environment is characterised by its 19th @-@ century red @-@ brick terraced houses , the infrastructure that was built to support these and the town 's former cotton mills – which mark the town 's skyline . The urban structure of Oldham is irregular when compared to most towns in England , its form restricted in places by its hilly upland terrain . There are irregularly constructed residential dwellings and streets clustered loosely around a central business district in the town centre , which is the local centre of commerce . In 1849 , Angus Reach of Inverness said : 
