Algeria contains the ancient Roman outpost of Timgad, a remarkably preserved planned city on the northern edge of the Sahara.
Timgad was founded around AD 100 by the Roman emperor Trajan as a military colony for veterans of the Third Augustan Legion. Its official name was Thamugadi, and its location helped Rome control routes through the Aurès Mountains and the surrounding frontier zone. The settlement was laid out on a strict grid, with streets meeting at right angles.
Although often called a desert city, Timgad stands in a semiarid highland environment rather than in the Sahara’s deepest dunes. Its ruins include a forum, theater, basilica, public baths, library, and a surviving triumphal arch dedicated to Trajan.
Timgad expanded beyond its original square plan as its population grew. Archaeologists value it because the dry climate and later abandonment left an unusually clear picture of Roman urban planning in North Africa.