Western Mediterranean from Marseilles

Every itinerary that says “Rome” means Civitavecchia, and the distance between the two is the entire planning problem of the day. The port is about fifty miles up the coast. Door to door (ship, shuttle, station, train, metro), you are looking at ninety minutes to two hours each way.

Pick one thing in Rome. With a twelve-hour call you get roughly six hours in the city. That is the Colosseum and the Forum, or the Vatican, or the centro storico on foot. Trying for two of the three is how people end up seeing lines.

Book skip-the-line entry in advance for whichever you pick. The Vatican Museums and the Colosseum both run timed entry and both sell out; a walk-up in July is a two-hour line in full sun.

The train is cheaper and often faster than a bus, but it is also the thing that strands people. Ship’s excursions have the ship’s guarantee behind them; a regional train does not, and Italian rail strikes are announced days ahead but are not rare. Check before you commit to going independently.

There is a real alternative to Rome. Cerveteri, twenty minutes down the coast, is a UNESCO Etruscan necropolis of round tombs cut into tufa that you walk down into. Tarquinia, the same distance the other way, has the painted tombs. Both are extraordinary, both are twenty minutes from the ship, and on a day when four ships are in you will have them to yourself.