Two volcanoes on the edge of Naples you can walk into. Astroni is an extinct crater filled with ancient forest and three lakes, once a royal hunting reserve. Monte Nuovo, above Pozzuoli, is the youngest mountain in Europe, born in a single week in 1538.
West of Naples, the Campi Flegrei, the "burning fields", are a vast volcanic caldera dotted with craters, hot springs and fumaroles. The ground here rises and falls with the activity below, a phenomenon called bradyseism.
The Astroni crater is the best-preserved of them: a near-perfect bowl about 250 hectares across, its slopes covered in holm oak, oak and chestnut, with three small lakes on the floor. For centuries it was a hunting reserve of the Aragonese and then the Bourbon kings, and the old royal walls still ring it. Today it is a nature reserve run by the WWF, with paths down from the rim to the lakes.
Monte Nuovo, at Pozzuoli, rose out of the ground in an eruption in September 1538 that lasted about a week, burying a village. It is now a wooded hill of about 130 metres with a nature park, and a walk of about an hour leads up to its crater.
The reserve's paths are marked; opening days and hours are limited, so check before you go.
Enter the reserve at the gate above Agnano and walk along the old Bourbon road, the Sentiero Borbonico, that descends inside the crater.
The path drops through dense woods of holm oak and chestnut, some trees centuries old, cool even in summer.
The largest lake has bird hides for watching herons, coots and kingfishers. Two smaller lakes lie nearby among reeds.
Loop back up through the forest to the entrance. For Monte Nuovo, head to Pozzuoli by bus or Cumana train.
Astroni is above Agnano, on the western edge of Naples: take a taxi or bus from Agnano station, or drive. Pozzuoli is on the Cumana railway and the metro line 2.
The reserve opens on set days with an entry fee, and may close after earthquakes in the Campi Flegrei. Check the WWF oasis's current schedule.
The Solfatara, Pozzuoli's Roman amphitheatre and the Serapeum market by the sea make a full Campi Flegrei day.
Naples practical notes →
The rim of the volcano that buried Pompeii.
Ischia's summit and a loop round pastel Procida.
Beech woods and the highest peak of the Lattari.
Bomerano to Nocelle, high above Positano.
Capri's wild west coast past three forts.
Wikimedia Commons photographs are used under their licences.
