Portus Magnus, Algeria

In the early modern period, Bethioua still housed several notable Roman mosaics and other artwork, most of which have since been removed to the museum at the provincial capital Oran.

The city of Portus Magnus stood on a hill overlooking the ancient port.

In present Bethioua, there remain some walls and buildings, rainwater cisterns, bits of Roman streets, and a small forum (50 by 40 meters or 160 by 130 feet).

The colonnades (porticus) and spa near some of the Roman villas probably constituted a palatial resort of the 3rd century.

During their invasion of North Africa, the Vandals destroyed Portus Magnus in AD 429 or 430.

Excerpt from a German map in one of Mommsen 's works, showing Portus Magnus on the coast of western Mauretania Caesariensis
Arzew 's colonial French coat of arms , showing its conflation by the French with the actual remains of ancient Portus Magnus to its southwest at present-day Bethioua