This page describes Ostia Antica, and some of the coastline west of Rome (including the area near the Fiumicino Airport)
A great, easy, inexpensive day trip from Rome, Ostia Antica offers a relatively uncrowded view of what a small ancient Roman city looked like. It was ancient Rome's port city, where traders from the Roman Empire brought their goods on the way to or from Rome. When the port silted up and the coastline moved west, the town fell into ruin.
Ruins of houses, shops, theaters, temples, and thermal baths
Interesting things in these buildings: ancient mosaics, toilets, millstones, etc.
Rick Steves can show you other ideas:
They both have a lot of similarities: Roman ruins, mosaics, public areas, etc
Why you might like Pompeii better: it's much bigger, more famous, and better-preserved
Why you might like Ostia Antica better: it's a bit quieter, less crowded, and cheaper
...but the main reason I would consider Ostia Antica is convenience from Rome: if you won't be spending more time in/around Naples, it's much, much quicker/easier to go to Ostia Antica (~30 min to Ostia Antica versus ~2.5+ hours to Pompeii, one way). Pompeii can be a brutal "day trip" from Rome, where you spend half the day going back & forth.
If you're staying in the Naples area, I also recommend checking out Herculaneum, which is less "epic" than Pompeii but better-preserved
More on Pompeii/Herculaneum on the Vesuvius Area page
Cheapest: Take the Roma Lido / Metromare metro! It's ~30-40 minutes from the Porta San Paolo train station (which is near the Pyramide Metro, or Ostiense train station) to the Ostia Antica stop...it only costs
Drive: ~30 minutes from central Rome without traffic, but depending on the time/day/starting point, it could take longer
Water, hats, comfortable shoes
A guide - while not necessary, a good tour guide can help the place "come alive" (at least consider a guidebook/audio guide, e.g. Rick Steves has a free audio tour linked from here, and Ostia-antica.org has some nice free materials...also this YouTube playlist is a great introduction)
Maybe: picnic lunch? (see below)
Not much...for example the closest restaurant to the entrance, Allo Sbarco di Enea, gets pretty bad reviews
...so consider packing a picnic lunch!
but see below for other ideas
Sora Margherita da Arianna "al Borghetto" - right in town, rec'd Fodors, good Google/TripAdvisor reviews
Ristorante Monumento - right in town, rec'd by NY Times in 2006, pretty popular on TripAdvisor
Il Gelataio Bar - well-reviewed on TripAdvisor
Iconic - another popular gelato place, across the street for Il Gelataio
Pizza da Michele - foccacia-style pizza, popular on Google Maps?
some of these are near the western entrance/exit from the ruins ("Ingresso Rimessagio")
Il Frantoio - Via di Castel Fusano 23, not bad Google reviews, ~17 min walk from the Ostia Antica train station
Golosi per Natura - gelateria in a shopping mall (Centro Commerciale Eschilo) that is very popular on TripAdvisor and Google
Ristorante Il Tino - across the Tiber in Fiumicino (~26 min walk from Ingresso Rimessaggio, the west gate of Ostia Antica), rec'd Gambero Rosso in 2017 (older 2016 article in English), one Michelin star (still in 2024)
? Bistrot QuarantunoDodici - cheaper/more casual bistro/bar associated with Il Tino, info@ristoranteiltino.com, lunch only, Michelin Bib Gourmand, Scatti di Gusto
Mammarò - in Fiumicino but ~23 min walk from ingresso Rimessaggio, rec'd Gambero Rosso in 2016 for inexpensive seafood
Equo Risto Fiumicino Ostia - near the Ingresso Rimessagio, good Google/TA reviews?
Not to be confused with Ostia Antica, the modern town of Ostia is on the coast, and at the end of the Lido/Metromar line...it has a number of places to eat:
Gastronauti - local/organic ingredients, casual take-away with some seats, rec'd Gambero Rosso in 2016, see this blog for photos
Molo Diciassette - innovative restaurant, colorful plates in whitewashed dining room, tasting menu or a la carte, mostly seafood but also some "turf", rec'd Gambero Rosso in 2017, Roma Today
Zenzero Biorestaurant - healthy/organic food
Landi Emanuele (Degustazione e Mescita) - small plates available at lunch, rec'd Gambero Rosso in 2017 (older 2016 article in English)
La Gnoccheria - Emilia Romagna food rec'd Gambero Rosso in 2017 (older 2016 article in English)
Oleonauta - olive oil shop rec'd Gambero Rosso in 2016
Le Golosità di Armando e Lucia - fancy deli rec'd Gambero Rosso in 2016
Michelino Fish Ristopescheria - fish shop that also sells cooked fish rec'd Gambero Rosso in 2016
Gelateria Carletto - rec'd Gambero Rosso in 2016
La Fraschetta (di Ponente) - Via della Corazzata 43, rec'd Roma Today
Ristorante The Legend - rec'd Roma Today
Bistro Toc Toque - rec'd Roma Today
L'Ostrica Pazza - a little ways south of main beach/town, rec'd Roma Today
?Da Zì Checco
?Pizzeria Il Campione
?Pesce Fritto e Baccalà
?Romolo dal 1976 - pizza
?La Casa del Tramezzino
?Bacchus Il Pesce E Il Vino
?Trattoria Le Romane
Romans love doing day trips to the beach; here are a few to consider:
La Vecchia Pineta - old school beach & restaurant rec'd Gambero Rosso in 2017, Puntarella Rossa in 2014
Oasi Naturista - beach/restaurant a bit south, rec'd Puntarella Rossa in 2014
Mediterranea - beach/restaurant a bit south, rec'd Puntarella Rossa in 2014
Dar Zagaja - beach/restaurant a bit south, rec'd Puntarella Rossa in 2014
way out near the coast, ~40 min drive from central Rome, ~30 min N of Ostia Antica, ~15 min taxi from Torre In Pietra-Palidoro which is 30-45 min on the regional train from Termini (towards Civitavecchia): Trattoria da Maurizio in Torrimpietra, Via di Torrimpietra,closed Mon, see this review of it "like being in an olive oil commercial", near a 13th century castle that also has a winery
Civitavecchia: Gelato Ingredienti Nobili - rec'd Gambero Rosso Gelateria d'Italia 2020
Ladispoli is between Civitavecchia and Fiumicino: The Cesar - fairly expensive place with organic/local ingredients, rec'd Michelin
...also see the Lazio page for more places to the north/south
On your way to/from Fiumicino "Leonardo da Vinci" airport (FCO)? Luckily there are a bunch of nice places to eat nearby!
Pascucci al Porticciolo - fancy place with one Michelin star
Il Tino - also fancy with a Michelin star
QuarantunoDodici - less fancy sister restaurant to Tino, rec'd Michelin
L'Osteria dell'Orologio - fish place rec'd Michelin
Pizzeria Sancho Dal 1969 - rec'd Gambero Rosso in 2017 and Slow Food Osterie d'Italia 2021 especially for supplì
Cielo FCO - rec'd Gambero Rosso in 2017
Pasticceria Patrizi - rec'd Gambero Rosso in 2017
Il Pinzimonio - rec'd Osterie d'Italia 2018 (not anymore in 2021)
Bar della Darsena - rec'd Gambero Rosso Gelateria d'Italia 2020
?? Osteria di Maccarese - a ways N of the airport in the tiny frazione of Maccarese, nice "refined rustic" style with quality ingredients and a mix of Lazio and Maremma (Tuscan coast) cuisine, Slow Food Osterie d'Italia 2021