ABERSYCHAN (5.b-ur-ziieh'an), an urban district, Mon mouthshire, England. The population in 1931 was 25,627. It lies in the narrow valley of Af on Lwyd between Pontypool and Blaenavon. Its situation on the iron field accounts for its early development, and when coal-mining became more important than iron smelting, Abersychan's prosperity increased, as the veins in the vicinity of the town produced some of the best steam coal in the country. The rapid growth of population has taxed all available building sites in the narrow valley bottoms and consequently the town has had to expand along the floor of the main valley and those of its small tributaries. Trade depression, unemployment and depopulation (since 1918) have affected Abersychan with the rest of the coal-field. Abersychan has sta tions on the Great Western Railway and London, Midland and Southern branch lines, connecting it with Newport and Brynmawr respectively. It is in the Pontypool parliamentary division.