Djemila is arguably the best-preserved Roman town in all of North Africa, and it has no business being this good. Set at 900 meters elevation in the mountains of northeastern Algeria, far from any major city, the site is a complete Roman colonial town frozen in time -- forum, temples, basilicas, triumphal arches, and streets still showing the ruts from ancient carts.
The Romans called it Cuicul and founded it in the first century AD as a military colony. What makes Djemila exceptional is its state of preservation and its setting. The town climbs a narrow ridge between two ravines, which forced a compact, vertical layout unlike the sprawling grid plans of most Roman cities. You walk through the Old Forum, past the Temple of the Septimian family, through the Arch of Caracalla, and into the newer southern quarter with its large Christian Basilica. The mosaics are extraordinary -- the site museum holds some of the finest examples in the Mediterranean, including detailed scenes of hunting, mythology, and daily life.
Getting to Djemila takes effort. The nearest city is Setif, about 50 kilometers to the southeast, and from there you will need to arrange a taxi or local transport. There is very little in the way of facilities at the site itself -- bring water and food. The altitude means it can be surprisingly cold in winter and pleasantly cool in summer, making it a year-round destination. Plan at least half a day to explore properly. This is a UNESCO World Heritage Site that sees a fraction of the visitors that comparable Roman sites in Tunisia or Libya receive, and that solitude adds enormously to the experience.