Pompeii is roughly two and a half hours from Rome each way, door to door: a high speed train to Naples, then the Circumvesuviana local line out to the ruins. It is a long day and a rewarding one, and the version with Mount Vesuvius on top is longer still. Leave Rome before eight, accept that you will get home after dark, and it works.
This plan is the full version: the excavated city through the morning, the crater rim in the afternoon, and the Sanctuary of Pompei in the modern town before the train back.
Is it worth a day trip?
Pompeii is larger and stranger in person than in photographs. You are not looking at a ruin so much as walking a street plan, with kerbs, shopfronts, bar counters and wheel ruts still in place.
Be honest with yourself about the walking. The excavated area is bigger than most people expect, the paving is ancient and uneven, and shade is scarce once the sun is high. Adding Vesuvius means a gravel climb to the crater rim at the end of an already long day.
Stay overnight in Naples or Sorrento instead if you are travelling in July or August, if you have small children or anyone who tires on rough ground, or if you also want Herculaneum, the Naples Archaeological Museum or the Amalfi coast. Two nights on the bay turns a forced march into a proper stay.
If this is your only free day, take it, but build it backwards from the last train, the way we set out in how to plan a day trip.
Getting there
Frecciarossa and Italo services run from Roma Termini to Napoli Centrale in a little over an hour, several times an hour for most of the day. Book these ahead on the operators' own sites, trenitalia.com and italotreno.com, because fares climb as departure nears.
At Naples you change to the Circumvesuviana, run by EAV, from the lower level at Napoli Garibaldi beneath Centrale. Take the Sorrento line to Pompei Scavi Villa dei Misteri, which is roughly 35 to 40 minutes and puts you at the Porta Marina entrance. Local tickets are bought at the station, not in advance.
A separate Trenitalia line serves Pompei station in the modern town, next to the Sanctuary, which is useful at the end of the day.
The day, hour by hour
09:30 Pompeii Archaeological Park. Entry is by timed slot with a daily visitor cap, so book on the official site rather than turning up. Bags are size limited, so leave the day pack in Rome. Pick up the site map at the gate, because the street grid is easy to lose track of.
10:00 Villa of the Mysteries. A suburban villa beyond the city walls to the north west, holding the cycle of red painted figures that gives it its name. Doing it first matters: it sits nearest the Villa dei Misteri entrance, so you see it before you walk east, rather than crossing the whole site twice. Check the site notices on the day, as individual buildings rotate in and out of access.
11:00 The Forum. The civic heart of the town, a long open rectangle with Vesuvius framed at the end of it, which tells you most of what you need to know about the day in 79 AD. The basilica, the temples and the market buildings all open off it. Stand still for a minute and work out the orientation here, and the rest of the site makes sense.
11:45 House of the Faun. The grandest private house in the city, big enough to fill a whole block, named for the small bronze dancing figure in its entrance court. The Alexander Mosaic was lifted from here and is in the Naples museum, with a copy laid in its place. The sequence of atrium, garden and colonnade is the clearest lesson in Roman domestic life on the site.
12:45 The amphitheatre. At the far eastern end, and the oldest surviving stone amphitheatre anywhere. The walk out along Via dell'Abbondanza, past bakeries and laundries, is half the reason to go. The Great Palaestra beside it is usually quiet, and from here you are walking back towards the exit rather than away from it.
15:00 Mount Vesuvius. Buses run up from Pompeii to the car park high on the mountain, and a gravel path climbs from there to the crater rim. Tickets for the Great Cone are sold online only, for a fixed time slot, so buy before you leave Rome. The park closes earlier in winter, so check the day's last entry.
17:00 The Sanctuary of Pompei. Back down in the modern town, the Pontifical Shrine of the Blessed Virgin of the Rosary is a huge late nineteenth century basilica with a bell tower you can see from the ruins. It is a working church and a calm place to sit for twenty minutes, a short walk from Pompei station for the train back towards Naples.
What to book ahead
Three things: timed entry to the archaeological park, a timed Great Cone ticket for Vesuvius, and seats on the fast train. Everything else can be decided on the morning.
Open this day trip in Tralendr
The whole plan is already built, in order, with every stop on a map. Open the Pompeii day trip from Rome in Tralendr and it loads without an account. Drop Vesuvius if the forecast is poor, cut the sanctuary if you want an earlier train, or send the link to whoever you are travelling with.
If you are weighing this against something gentler, see how far is too far for a day trip, or all our day trips.