On entering Lazio outside Minturno, the Via Appia follows the curve of the Gulf of Gaeta and passes through Formia, a bright and breezy seaport and resort at its northern extreme with a sheltered harbour. At the back of the town the land climbs steeply into the foothills of the Arunci mountains and the same ridge carries a section of the Naples to Rome railway on a revetted embankment.

Cicero was among many elite Romans to have a villa at Formiae. He was assassinated on the Appian Way, just outside the town in 43 BC. Formiae also had an amphitheatre. When the remains were rediscovered in 2011 embedded in and overshadowed by the railway embankment (Perhaps the street named Via Anfiteatro might have been a clue?) it was announced that excavations would commence. From the state of the site in 2025, they dont seem to have progressed much.

Via Anfiteatro is a herring as red as any that ever swam in the Gulf of Gaeto because it rises from the spine road of the old town (Via Ferdinado Laranga) and comes to a halt in a courtyard surrounded by apartment blocks. More promising is the road a few metres east - Via Venti Settembre. This starts beside some surviving Roman warehouses adjacent to the inner harbour, crosses Ferdinado Laranga, and ends in a barrier. Hopping over this you enter a disused car park with a gracefully curved south-east boundary. At the back of the paved area to the north is a chain link fence through which you can glimpse some Roman Arches - currently unkempt and overgrown, beside which are concealed foundations of the amphitheatre cavea.