Ercolano

The eruption of AD 79 treated the two Roman towns differently. Pompeii took 3 to 4 metres of ash, hot enough to scorch organic material but not to seal it. Herculaneum, closer to the mountain and down at the shore, was hit by repeated pyroclastic surges and ended up under a mud flow that cooled hard around everything it touched: roofs, furniture, scrolls, upper floors.

That difference in burial is the reason one site kept its wood and the other did not: the carbonised wooden screen of the House of the Wooden Partition, the wooden bed in the House of the Carbonised Furniture, and the second-storey overhangs are all here because the mud sealed rather than scorched them. The site was named UNESCO World Heritage in 1997, jointly with Pompeii and Torre Annunziata. The suburban villa attributed to Julius Caesar's father-in-law, Lucius Calpurnius Piso, once stood on the ancient seafront, now buried well inland under the weight of the deposit.

Inside it, roughly 1,800 carbonised papyrus scrolls were recovered, including the entire Epicurean philosophical library of Philodemus of Gadara. That find, the largest single ancient library ever recovered, is still being unrolled with multispectral imaging at the Officina dei Papiri Ercolanesi in Naples, and it is the building the J. Paul Getty Museum in Malibu replicated 1:1 as its main structure.

Along the old shoreline nearby, the arched boathouses hold the remains of 300 fugitives killed by the 500 degree pyroclastic surge while they waited for a rescue that never reached them, discovered in the 1980s and 1990s and now the most-photographed image of that moment. The modern town sits directly on top of the ancient one, 50,000 people on the lower slopes of the volcano, with the excavated ruins sunk below current street level in a pit at the centre of things. Excavation has gone on since 1738, when Charles of Bourbon began it, and continues piecemeal now.

To the east, the ground rises toward the national park and the Gran Cono crater, reached by a half-day hike from the upper car park with reservation required. To the west, the road along the old Golden Mile strings 122 Bourbon-era villas, built between the 1730s and 1820s by the Naples aristocracy, toward the coast; Villa Campolieto, designed by Vanvitelli in 1763 and now a cultural centre, and Villa Favorita, a former royal residence, are the ones open to visitors. Upper slope, buried town, and shoreline road are three bands of the same landscape, each shaped by proximity to the same mountain.

The town's food follows the same geology: spaghetti alle vongole, mozzarella di bufala, pomodorino del piennolo del Vesuvio DOP grown on the volcanic slopes, and Lacryma Christi del Vesuvio DOC red and white from vineyards on the same soil. What holds the place together is that the volcano is not backdrop here. It is the reason the ruins are intact, the reason the villas needed a gateway road, and the reason the food tastes the way it does.