Abstract Isola Sacra is the name of an artificial island located approximately 20 km southwest of Rome, Italy, between the port cities of Ostia and Portus Romae . The island was created during the construction of the Fossa Traiana in the mid‐first century ce to connect the city of Rome to Portus along the coast via the Tiber River. Isola Sacra is best known for the monumental Roman tombs that line traces of the Via Flavia between Portus and Ostia.