The hook
Two Roman towns buried alive by Vesuvius in AD 79 and dug back out, one enormous and famous, the other smaller and far better preserved, with wooden doors, upstairs floors, and carbonised food still in place.
01Why it's worth it
When Vesuvius erupted it destroyed the towns in opposite ways, and that is the key to visiting well. Pompeii was smothered in ash, which preserved the street plan of a whole city: forum, brothels, bakeries, election graffiti, and the plaster casts of people caught in their last moments. It is vast, and its size is the point, but it is also crowded, hot, and exhausting. Herculaneum, closer to the volcano, was sealed under a deep surge of hot mud that carbonised rather than burned, so it kept things Pompeii lost, upper storeys, wooden furniture and doors, roofs, even loaves of bread. It is a fraction of the size and a fraction of the crowd, and standing in a two-storey Roman house with the original beams overhead lands harder than any single thing in Pompeii. Do both if you can, and give the smaller one real attention.
02How to experience it
Start early or come late; there is almost no shade and midday is brutal. If you only have energy for one, Herculaneum rewards it with depth and calm, while Pompeii rewards a half-day of wandering with a plan and good shoes. The archaeological museum in Naples holds the best frescoes and mosaics lifted from both, so it completes the picture.
From the locals
Italians and long-time Italy hands put it on the short list of things that must be seen, not merely enjoyed: asked to name the country's essentials, an American with "30 years of travel and experience in Italy" answered simply — "da visitare: Firenze, Roma, Pompeii." To visit: Florence, Rome, Pompeii.