Quiz: Remember the definition of mal de mer?
gemeente (municipality), southeastern Netherlands. It lies just northeast of Maastricht. Situated on the site of the Roman settlement Coriovallum (with remains of a Roman bath), it is essentially a modern town that grew rapidly as the centre of the Dutch coal-mining district. With supplies of coal running low or too deep, however, the mines were closed by the early 1970s. Heerlen has developed into a light industrial district; manufactures include petrochemicals, automobiles, briquettes, iron, stoneware, and cement. There are geological and archaeological museums, the latter in the modern town hall (1938-48). St. Pancras Church (1180) has a tower that was formerly part of the Herle fortress (1390). Pop. (2007 est.) mun., 90,537; urban agglom., 256,164.