The area between Portus and Ostia Antica was transformed into an artificial island by Emperor Trajan, creating a canal that linked the Tiber to the sea (Fossa Traiana, now Fiumicino Canal). Merchant ships arriving from Egypt and Africa were able to reach Ostia using this canal. The island was originally much smaller but it has been constantly growing due to the alluvial activity of the Tiber. Its area almost quintupled since the antiquity.
In the 1st century AD., a road linked the two ports, crossing through the island and becoming the main road axis. The Isola Sacra Necropolis grew up alongside the road, that was discovered between the 1920s and the 1940s, while the land was being reclaimed. Some of the necropolis buildings have two storeys, elaborately decorated with paintings, stucco work and mosaics.
The left side of the Fossa Traiana was a residential area of Portus. Near the Fiumicino Canal, by the bridge that crossed over to Portus, the so-called Terme di Matidia can be seen. The core of the complex built in the middle of the 2nd century and used until the 6th century. The Basilica of St. Hippolitus was built between the end of the 4th and the beginning of the 5th century. The building was divided into three naves by two rows of columns.
- "History and territory of Fiumicino" (in (Italian)). Comune.fiumicino.rm.gov.it. 2012-05-29. Retrieved 2012-10-12.
- Calza, G. 1940. La necropoli del Porto di Roma nell' isola Sacra. [Rome] La Libreria dello stato.
- D'Ambra, E. 1981. "A work 'ethic' at Ostia: the Isola Sacra reliefs." Thesis (M.A.)--University of California, Los Angeles--Art History.
- Prowse T., Schwarcz H., Saunders S., Bondioli L., and Macchiarelli R. 2005. "Isotopic evidence for age-related variation in diet from Isola Sacra, Italy." American Journal of Physical Anthropology. 128(1):2-13.
- Quilici, L., S. Quilici Gigli, R. Talbert, T. Elliott, S. Gillies. "Places: 422948 (Isola Sacra)". Pleiades. Retrieved March 8, 2012 10:35 am.