Cothon (Civ4)/Civilopedia

Of Phoenician origin, the city-state of Carthage was a mighty sea power, with a trading empire stretching across much of the Mediterranean. Carthage's wealth (and survival) depended upon the quality of its navy and merchant fleet. To protect its fleet from attack and the elements, and to improve and speed construction of new vessels, Carthage constructed two artificial harbors ("cothon") in the city, a massive effort that required the excavation of some 230,000 cubic meters of earth. One harbor was for the merchant fleet; the second was for the Carthaginian navy.
According to ancient historians, "The harbors 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 for 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 harbor and the island. These embankments were full of shipyards which had capacity for 220 vessels."