The best day trips from Napoli all lie under the volcano and all work by train. Pick one of them, or two if you start early.
The Roman city buried by the eruption of Vesuvius, with streets, houses and frescoes laid out as they were found. Allow about four hours.
Tip: Admission is €20 for the city and €25 with the villas. From 15 October the last entry is 3.30 pm. Bring water and a hat, because the shade is thin, and visit the Archaeological Museum first. The official site has the current opening times.
Weather: Pompei
A smaller Roman town buried deeper, which kept its wooden beams, upper floors and painted colour. It takes about three hours.
Tip: Admission is €16, and EU citizens aged 18 to 24 pay €2. The site is open daily with winter hours from 15 October. See the Herculaneum site for hours.
Weather: Ercolano
A walk up to the crater rim of the volcano that buried the towns below it, with the whole bay spread out underneath.
Tip: Tickets are online only, at €11.68 and for timed slots. The last entry is 3 pm in November and 16:00 in October, so start in the morning and plan around a clear sky. The national park site shows the available slots.
Weather: