Portus Magnus, Algeria

Portus Magnus ("Great Port") was a Roman port and colony in western Mauretania Caesariensis near Portus Divinus. Its ruins are now under and around Bethioua in Algeria's Oran Province. 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.

Archaeological site data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).