ABERTILLERY, urban district, Monmouthshire, England, 16m. N.W. of Newport, on the G.W.R. Pop. (1891) 10,846; (193') 31,799. It lies in the mountainous mining district of Mon mouthshire and Glamorganshire, in the valley of the Ebbw Fach, and the large industrial population is mainly employed in the numerous coal-mines, iron-works and tinplate works. The upper reaches of the valley were formerly important as iron smelting regions and coal was worked early at Abertillery. This region, like most of South Wales, has suffered badly in the trade depres sion following the World War.