Utica, which stood in ancient times near the estuary of Tunisia’s only perennial river, was traditionally supposed to be the third Phoenician colony in the west (founded in 1101 BC, shortly after Gadir and Lixus). The city was for most of the period for which we have archaeological evidence (from the 7th century BC to the 8th century AD) second in importance in this region only to Carthage, and flourished as a relatively free city under both Carthaginian and Roman hegemony. Its situation at the head of the Mejerda valley, the corridor to the rich imperial estates and the fertile grain-producing uplands of the Tunisian Tell, made it one of the most important ports of Roman North Africa. The site now lies 10 km from the sea and the most recent geological studies suggest that the port had already begun to silt up by the late antique period, as a result of the river Mejerda changing course from its older bed to the east of Kalaat al-Andalous.
Although the basic outlines of some elements of the city plan are clear, the urban topography of Utica as a whole is poorly understood. The main public buildings identifiable on the site include the aqueduct, reservoir cisterns, one or possibly two amphitheatres, a theatre, a circus, stadium or hippodrome on the southern edge of the site, and possibly a second to the north-west, and a large set of baths in the NW of the site (wrongly interpreted at times in the 19th and 20th centuries as a Punic or Phoenician port). In what appears to be the monumental centre of the city a large civic structure, possibly a basilica, and a temple are known, adjacent to a large open area, probably the forum. A handful of rich houses with mosaics and ornate architectural decoration have also been excavated to the east and south of the centre. To date, however, the precise line of the Roman coastline and the location of the port are unclear. The silting of the Medjerda river estuary and the consequent progradation of the coastline mean that the former port city now lies 10 km from the nearest point on the coastline, 11 km from the edge of Lac Ichkeul, and 17.3 km from the point at which Lac Ichkeul communicates with the sea. Even the outer limits of the site – the city walls, and the extent of occupation – are not fully certain.