ISERLOHN, chief town of a circle in the government district of Arnsberg and province of Westphalia, Prussia, is situated on the Baar, in a bare and hilly region, 17 miles west of Arnsberg. Among the principal buildings are the town-church, the synagogue, the hospital, the orphanage, the poorhouse, and the new town-house. There is a real school of the first class, and a commercial school for the province. Iserlohn is one of the most important manufacturing towns in Westphalia. Its chamber of commerce was founded in 1850. Both in the town and neighbourhood there are numerous foundries and works for iron, brass, steel, and bronze, while the manufactures include wire, needles and pins, fish-hooks, machinery, umbrellaframes, thimbles, bits, furniture, chemicals, coffee-mills, and pinchbeck and britannia-metal goods. A part of the town has recently been endangered by the calamine mines beneath. Iserlohn is a very old town, its guild of armourers being referred to as “ancient” in 1443. The population in 1875 was 16,838.