district, administrative and historic county of Essex, England. It occupies the northwestern corner of the county, where it borders Cambridgeshire and Hertfordshire. A low ridge of chalk hills runs from southwest to northeast through a rolling countryside. The district is largely rural. The main town is Saffron Walden; there are also many smaller old parishes, such as Thaxted, Great Dunmow, and Stansted Mountfitchet. The region has long been a residential area for affluent commuters to London. Stansted airport has become London's third major field, after Heathrow and Gatwick. Area 248 square miles (642 square km). Pop. (2001) 68,940.