Ostia

What is there today

A whole town of brick to walk through: houses, shops, warehouses and apartment blocks, sometimes several storeys high (fr.wikipedia), with floor mosaics still in place in many buildings (de.wikipedia). The walled town covered about 69 hectares (en.wikipedia; it.wikipedia). Published estimates of how much of it has been dug differ, from a third (en.wikipedia) to two-thirds (de.wikipedia), but either way the excavated part is large: by the gazetteers’ points it is about a kilometre from the Porta Romana at the Rome end to the Porta Marina at the sea end, along the main street, the Decumanus Maximus. Much of the marble that once faced the public buildings was carried off over the centuries (en.wikipedia; it.wikipedia), and on the whole the ruins are in rather poor condition (de.wikipedia).

The ticket office is at the eastern end of the site, the Rome end (OpenStreetMap). From there, these are the buildings the sources single out, roughly in the order you meet them.

From the Porta Romana to the theatre. Outside the Porta Romana, tombs line the Via Ostiense: this was the oldest and largest of Ostia’s cemeteries, used from the 2nd century BC to the late empire (it.wikipedia). Inside the gate, the Baths of Neptune were rebuilt under Hadrian, who gave two million sesterces, and dedicated in 139 under Antoninus Pius; they are known above all for their black-and-white mosaics; the one that gave them their name shows Neptune driving his sea horses among tritons and sea creatures (it.wikipedia; de.wikipedia). In the same quarter is the barracks of the vigiles, the town’s fire brigade, rebuilt under Hadrian around a large courtyard (it.wikipedia; de.wikipedia).

The theatre was first built by Agrippa under Augustus and rebuilt in brick at the end of the 2nd century AD, when it held about 4,000 people; it was restored in 1927 (it.wikipedia) and is still used for performances (de.wikipedia). Behind the stage lies the Piazzale delle Corporazioni, a square of about 110 by 80 m inside a portico with some 70 small rooms (de.wikipedia). The floor mosaics in front of the rooms show ships and name shipowners, traders and ports such as Alexandria and Sabratha. What the rooms were for is not certain, but they were most likely the offices of shipowners and merchants from port cities around the empire (fr.wikipedia; de.wikipedia). Close by, the four small temples known as the Quattro Tempietti go back to the Republic (Pleiades).

The forum. The forum is at the heart of the oldest town, where the two main streets cross (it.wikipedia). At its north end the Capitolium, the town’s chief temple, built for Jupiter, Juno and Minerva around 120 under Hadrian, still stands about 17 m high on its podium and rises above every other ruin; a broad flight of steps, partly rebuilt from the original material, leads up to it (it.wikipedia; de.wikipedia). Opposite is the Temple of Rome and Augustus, built under Tiberius, and the Basilica and the Curia, where the town council met, stand on the western side (en.wikipedia; de.wikipedia). South-east of the square, the Forum Baths, built about 160 by the praetorian prefect Gavius Maximus, were the largest in Ostia (de.wikipedia; it.wikipedia). Nearby are the Round Temple, probably for the cult of the emperors and now poorly preserved (de.wikipedia; it.wikipedia), and the Horrea Epagathiana, a warehouse of about 145–150 that still carries the names of its two owners over the door and is in good condition, unlike the much larger Grandi Horrea, the main grain stores (de.wikipedia).

Apartment blocks, houses and mithraea. North of the forum, the Caseggiato di Diana is an apartment block of the first half of the 2nd century, built around a courtyard and perhaps five storeys high (it.wikipedia), and one of the best-preserved of its kind, with a fountain, a latrine and a small mithraeum inside (Coopculture), but it opens only on the Sunday tours below. Rich houses of the 4th century, such as the House of Cupid and Psyche, still have walls covered in marble panels and floors of coloured marble (en.wikipedia). The cult of Mithras was popular in Ostia, where eighteen of its shrines have been found (en.wikipedia); the one under the Baths of Mithras, reached down a staircase, is the best preserved (fr.wikipedia; de.wikipedia).

Towards the sea. In the west of the town, the Baths of the Seven Sages, built under Hadrian, centre on a round hall that once had a dome, with a hunting mosaic on its floor (de.wikipedia). The Garden Houses, built around 128, were two blocks of four houses set in a garden with six fountains (Pleiades), and the House of the Muses among them keeps wall paintings that are well preserved for Ostia (de.wikipedia). Beyond the Porta Marina are the tomb of Gaius Cartilius Poplicola, a leading citizen, from about 30–20 BC (Pleiades), and at the southern edge of the site the synagogue, built under Claudius in the 1st century and used into the 5th; it is the oldest synagogue yet found in Europe (en.wikipedia; Pleiades).

The Museo Ostiense. Inside the site, in the Casone del Sale, a 16th-century building of the papal salt works, the museum has been rearranged in 12 rooms on the town’s origins, imperial power, its public life, its people, its cults, its cemeteries and its houses (the operator). It opens later and closes earlier than the excavations.

Closed, or open only on some days. Many painted interiors are kept closed because they are fragile. The park’s ticket and tour concessionaire, Coopculture, opens some of them on guided tours in Italian on the second, third and fourth Sundays of the month, 11.00 to 13.00, for €7 on top of the entrance ticket; October 2026’s three tours take in the Caseggiato di Diana and the Insula of the Painted Ceiling, the Baths of the Seven Sages and the Insula of the Painted Vaults, and the Mithraeum of the Seven Gates with the Insula of the Eagle (Coopculture). The Laurentine necropolis, a cemetery of freed slaves outside the Porta Laurentina, is closed for maintenance and restoration, and the Christian basilica at Pianabella, south of the walls, was covered over again after it was excavated in 1976 (the operator).