an ancient Tunisian city, now in ruins, 110 km southwest of Tunis. Well known as long ago as the fourth century B.C., Dougga possesses architectural structures from the Numidian period (third to second centuries B.C.)—the mausoleum of Ateban and the remains of city walls—and from the Roman period (first century B.C. to fifth century A.D.)—ruins of a forum, towers, a theater, a circus, the triumphal arches of Septimius Severus and Alexander Severus, temples, and houses with mosaic floors and vaulted cisterns.