How it began
Carthage, a Phoenician colony on the coast of present-day Tunisia, built a twin harbor known as the Cothon on its southern shore, near the modern suburb of Salammbo. Archaeological evidence and ancient texts date the installation to the late third or early second century BCE, and pottery from the excavations points to the 2nd century BCE. Both basins were dug out artificially from a coastal lagoon and together covered about 32 acres.
How it works
Ships entered through one opening about 20 meters wide that could be closed with iron chains. They came first into a rectangular merchant harbor of roughly 150 by 400 meters. A narrow channel led on to the circular military basin, 325 meters across, hidden behind a double wall. Roofed ship sheds ringed the basin like spokes, each holding one warship on a slipway, with stores for oars and rigging above. An artificial island about 125 meters wide in the center carried the admiral's tower.
Who pushed back
During the Third Punic War the Roman general Scipio Aemilianus built a mole across the harbor mouth in 147 BCE. The Carthaginians built about 50 new warships inside the sheds and cut a new channel to the sea, but the fleet was lost. Roman troops took the harbor walls in the spring of 146 BCE, the city was destroyed and the basins were filled in.
What changed first
The Greek historian Appian wrote that the harbor could hold 220 warships. Modern archaeologists such as Serge Lancel put the figure at about 170 to 180, and excavated remains suggest some 30 slipways on the island and 135 to 140 around the perimeter. The sheds measured 30 to 48 meters long and about 6 meters wide. The layout let crews haul ships out for repair and kept the fleet out of sight of traders in the outer port.
Where it stands today
The site lay under the suburbs of Tunis until UNESCO launched the Save Carthage campaign in 1972. From 1974 a British team led by Henry Hurst excavated the island and the north side of the basin and found the foundations of the ship sheds and their slipways, matching Appian's account. The circular harbor survives as a lagoon with the admiral's island at its center.
