an ancient Celtic habitation site on the right bank of the Danube, near Hainburg, Austria. Under the emperor Augustus, Carnuntum was used as a camp during the war with Maroboduus (a.d. 6). Later, it acquired the significance of an important fortification on the Danube frontier of the Roman Empire. In 73 it was enclosed with a stone wall and became an outpost for Roman legions. During the Roman wars with the frontier tribes, Carnuntum was destroyed and then reconstructed several times (the last time in 375); it was razed once and for all circa 400. The site was excavated in the 1920’s and 1930’s. Two amphitheaters, a praetorium, a forum, thermae, a mithraeum, and other buildings were discovered.