Aquileia was the ninth most important and biggest city of the Roman Empire and the third in Italy: the large quantity and miscellaneous variety of Roman remains is self explanatory and includes trading infrastructures (harbour, roads), as well as residential or funeral ruins (private houses' mosaics and cemetery). Much has still to be retrieved and studied, but archaeologists - who keep working at excavation sites year after year -have reconstructed with a good degree of certainty the internal disposition of the city buildings: thermal baths, anphitheatre, circus and the alleged imperial palace, known from documents dating back to the times of Costantine.

The harbour is situated beyond the basilica, and stretches along the Via Sacra (Sacred Road), inaccurately called so probably for the rows of cypresses on its sides. In fact the road follows precisely an embankment in the middle of the river Natissa basin, today only a very little canal. It is still possible to see long stretches of the quays, paved and equipped with mooring rings, several lined up docks easily reached through ramps, and defense constructions.

Behind the harbour, as mentioned, there is the forum, that, together with the forensic Basilica, is located at the intersection between Via Julia Augusta and Via Gemina, the roads that crossed the town from North to South (card?) and from West to East (decumanus maximus) respectively. At the beginning of the 1930s, when the port was dug up to surface, the finds were given back a renewed splendour, building ex novo columns in red brick topped with the Corinthian capitals found there.

As regards Aquileia's Roman private houses several ruins with floor mosaics (Cossar, Rizzi and CAL floors are the most remarkable); as for funerary sites, five grave sites, dating back to the first three centuries a.C., were found in the so called cemetery area; other finds are in the Museum of Archaeology.