The ancient artificial harbour--the Cothon--is represented today by two lagoons north of the bay of al-Karm (el-Kram). In the 3rd century BC it had two parts, the outer rectangular part being for merchant shipping, the interior, circular division being reserved for warships; sheds and quays were available for 220 warships. The harbour's small size probably means that it was used chiefly in winter when navigation almost ceased.

In the second century AD Appian of Alexandria wrote a history of the Roman Empire. Following an earlier account by Polybius, he gave this account of the port area of Carthage just before its destruction by Rome (Libya 96):

    The harbours had communication with each other, and a common entrance from the sea seventy feet wide, which could be closed with iron chains. The first port was a merchant vessels, and here were collected all kinds of ships' tackle. Within the second port was an island, and great quays were set at intervals round both the harbour and the island. These embankments were full of shipyards which had capacity for 220 vessels. In addition to them were magazines for their tackle and furniture. Two Ionic columns stood in front of each dock, giving the appearance of a continuous portico to both the harbour and the island. On the island was built the admiral's house, from which the trumpeter gave signals, the herald delivered orders, and the admiral himself oversaw everything.


    The island lay near the entrance to the harbour and rose to a considerable height, so that the admiral could observe what was going on at sea, while those who were approaching by water could not get any clear view of what took place within. Not even incoming merchants could see the docks at once, for a double wall enclosed them, and there were gates by which merchants' ships could pass from the first port to the city without traversing the dockyards. Such was the appearance of Carthage at that time.

Excavations have established Appian's description and that the ports of Carthage were magnificent technical achievements. Some 120,000 cubic meters of earth were moved to make the rectangular merchant harbour and another 115,000 to make the circular harbour.

The earth and timber spillways in which ships from the water's edge were brought up to the central island of the military port have been found. Much of the area seems to have suffered from a renewed elevation in sea level -- perhaps in the Roman imperial period -- and much filling-in occurred in the 6th c AD.