If you’re not going south to Pompeii on your journey through Italy, then this ancient Roman port is the next best thing. In fact, in some ways it’s better because it’s less crowded so you can really feel what daily life was like in Rome rather than the 21st century tourist vibe.
Ostia Antica was founded at the mouth of the Tiber River in the 4th century BC and became an important port city both for trade and defense. In the 5th century AD the city was abandoned after malaria and barbarians simultaneously attacked. River silt did to the city what lava did in Pompeii – covering it and preserving streets and buildings. The town was reinvigorated by Pope Gregory IV in the 9th century to once again become a major port, but time and tide literally turned their back on the city as sea levels dropped and river silting became worse until the port eventually moved; these days Ostia Antica lies 1.8 miles (3km) from the sea!
The Romans loved their bath houses and Ostia Antica had twenty! One of the most impressive to see is the Terme di Nettuno (Bath of Neptune) which has well-preserved mosaics of the sea-god in his chariot driving his seahorses surrounded by mermaids, mermen and so on. There is also a good mosaic of athletes training in the central Palaestra (courtyard). From the top of the amphitheatre you can look out over the large town and see the long main street Decumanus Maximus and the forum, the Piazzale delle Corporazioni. Also well preserved is an example of that other Roman obsession: eating. The Thermopolium is basically a hot food restaurant with a central bar and a frescoed menu on the wall. Ostica Antica is only about half an hour from Rome by train and worth the trip.