CASTLETON, a township, in that part of the parish of ROCHDALE which is in the hundred of SALFORD, county palatine of LANCASTER, 2 miles (S. E. by S.) from Rochdale, containing 7894 inhabitants, many of whom are employed in the woollen and cotton manufacture. The name is derived from an ancient castle, one of the twelve Saxon castles in the county, the keep of which still remains. Part of the town of Rochdale is situated within this township, where are the cisterns for supplying the town with water, and the gas-works for lighting it. The inhabitants participate in the benefactions made to the parish both for scholastic and charitable purposes.