Newcastle-under-Lyme, city (1991 pop. 73,208) and district, Staffordshire, W central England, on the Lyme River. Construction materials, apparel, computers, electric motors, and machinery are manufactured in the city. There are ruins of a castle built (12th cent., the "new castle" of the city's name) under Ranulf, earl of Chester. The 13th-century parish church was redesigned in 1876 by George Gilbert Scott. Within the district, Chesterton has extensive Roman remains.

Ashton-under-Lyne, town (1991 pop. 43,605), Tameside metropolitan district, NW England, in the Greater Manchester metropolitan area on the Tame River. Its industries include engineering, leather, plastics, textile production and processing, brewing, and the manufacture of diesel, gas, and oil engines.