Roman road - Once you enter the ruins, the first thing kids will see is a beautifully preserved Roman road, lined with smooth black basalt stones. The road, the Decumanus Maximus, runs the length of the ruins, about two kilometers. Ostia was protected by defensive walls, and entered by three gates. The Decuman road passses through the Porta Romana on the eastern edge, the city ended at the Porta Marina on the western end (which was also the coastline at that time).

Necropolis - The first section of the Decuman road is lined with a necropolis, where people were buried. Looted long ago by tomb robbers, it's fun to wander among the tombs, which would have held urns with ashes or niches for whole bodies (Tomb of the Archetti).

Baths of Neptune - The baths have exuberant black and white mosaics of the sea god Neptune and fabulous sea creatures, dolphins, mermen and sea nymphs. These baths were built by Hadrian, along with an arena for athletes (which has a super mosaic of two guys boxing).

Theater - Plays were performed in the large open amphitheater that could hold an audience of 2,500 people. The theater is in great shape as it's been restored, and plays are produced here in the summer.

Plaza of the Guilds - Behind the amphitheater is the Plaza of the Guilds (also called the Forum of the Corporations). Around this large quadrangle, all the trading and shipping businesses had their offices. Today, you can see black and white mosaics, symbols of each trading group - shipping owners are symbolized with different kinds of ships, an importer of wild beasts (for the games in Rome) is symbolized by an elephant, rope-makers by rope, amphora or date palms for importers of those products, etc. In the center of the plaza is a Roman temple.

Mill of Sylvanus (Via dei Molini) - Head up Via dei Molini to visit a bread bakery, rooms with the mills for grinding corn (you can see the stone mills, two conical sections fitted together), where the dough was kneaded, and counters at the front of the shop where bread was sold for the Rome market.

House of Diana - On the street next door is the House of Diana, a bunch of multi-story apartments (insulsa). The buildings would have been four stories high, with shops on the first floor, living apartments on the other floors, and latrines (bathrooms) and cistern for water close by.

Thermopolium - Kids can relate to the Termopolium, a snack bar that served hot food and drinks. One area is a kitchen, with a built-in wood burning stove and storage jars. A marble serving counter has shelves and basins to wash dishes. Outside is a courtyard where customers could sit in good weather.

Latrines - Across the Decuman road are the public latrines, very spiffy and modern looking marble toilets. Seating was very social, and running water available. Romans didn't use toilet paper, but they had sponge sticks. While you're there, also stop into the Forum Baths next door, very large and spacious, with hot steam baths and cool pool.

Forum - Temple of Augustus and Rome and the Capitolium - You can't miss these two big temples on either side of the Decuman road. The Capitolium, with wide steps and high walls, was a temple to Juno, Minerva and Jupiter, and it's in great shape because Hadian rebuilt the temple in the 2nd century AD. The Temple of Augustus and Rome across the way is a century older, but much crumblier - the big tree and grassy area are a good place to picnic, or you might see a local scout group doing team activities on the grass.

House of the Lararium - Right down the road from the Capitolium, stop briefly into the House of the Lararium. There's a well-preseved brick niche (in a diamond pattern) - this niche would have held statues of the Roman house gods.

Fishmonger's shop - At the fork in the road, check out the fishmonger's shop (Tabernae of the Fishmongers). It looks remarkably efficient, with a spiffy marble table and big water tank behind it. The mosaic floor is decorated with big black fish that looks like a swordfish.

Christian Basilica - Further down the Decuman road is a Christian basilica, built in the 4th century AD. It might not look quite like the usual Christian church, with its Greek style columns down the center, and two brick apses.

Museum and snack bar - The Museo Ostiense displays sculptures excavated from the ruins, including some Mithraic statues (the cult of Mithras was popular in Ostia). Out in front of the museum is a shaded picnic table, and next door is a snack bar with drinks, pastries and sandwiches.

Town of Ostia - A short walk from the entrance to the ruins is the charming little town of Ostia. Check out the Castello di Giuli II, a large Renaissance castle, which defended the Tiber River and access to Rome. The castle is open 10:00 - noon daily, stop in to see it before you visit the Ostia Antica ruins. Also in the town are fruit stands, ice cream, and a couple of restaurants.

Tip: The ruins are closed on Mondays. To get to Ostia Antica, take Metro Line B to EUR Magliana, transfer to the metropolitan railway line, and get off at the Ostia Antica stop. From the train station, just walk over the blue bridge, and you'll see signs for the ruins.