Egnazia hold the original urban plan, with public and religious monuments built during the years.
At the end of the 4th century B.C., the area in which the settlement is concentrated was surrounded by a boundary wall. That fact marked the beginning of a transformation from settlement to town due to the strong development of the Messapian centre. Since the second half of the 2nd century B.C. the town underwent a new modification, which affected also the ager up to the Augustan period. That one is the phase in which the urban space was mainly structured inside the walls starting from the road system. The via Minucia gained a great prominence. It crossed the town from the western to the eastern sector, separated the public areas (mostly concentrated between the road and the acropolis) from the spaces addressed to housing and manufacturing, led to Brundisium and became a primary way in the organization of that territory.
This kind of urban structure contained the typical areas of a Roman city where, particularly in the last Republican period and at the beginning of the Augustan period, public buildings were mainly concentrated. That explains the great relevance of the port but also the building of a forum with its attached monuments such as the public basilisk and the baths.
In the first half of the 2nd century A.D., this kind of system continued to exist without meaningful changes. The road system was restored through the construction of the via Traiana, partly on the route of the old via Minucia. The effects of this kind of intervention were more evident inside the town, where the invasive building site for the road construction caused an extensive process of remodeling which conformed to the plan of city already set in the previous century, renovated different sectors, and was concentrated in the areas near the road also with architectural construction with high monumental value.
At the end of the IV century, the research, enriched by interesting data about the territory, has demonstrated a marked change in the town settlement.