district, administrative and historic county of Cambridgeshire, England. The district, in northern Cambridgeshire, covers only a part of the drained area of the Fens, from which it takes its name. In addition to Wisbech, the administrative centre, it includes the small towns of Chatteris, March, and Whittlesey, but the district is mainly rural, with dispersed farms. Area 213 square miles (552 square km). Pop. (2001) 83,523.