Monte Rotaro Fumaroles

Where they are

Walking through the Bosco della Maddalena (Maddalena Wood), on the ridge of Monte Rotaro, you may notice small puffs of steam rising from the ground, especially on cool, damp mornings. These are the Rotaro fumaroles, scattered along the trails that link the wood with the Fondo d'Oglio crater. There is no single signposted viewing point: you come across them along the Maddalena Trail and the Fondo d'Oglio and Montagnone trail.

What fumaroles are

A fumarole is a spot in the ground from which water vapour and gases of volcanic origin escape. Water circulating underground on the island is heated at depth by the volcanic system and rises to the surface as steam along faults and fractures. According to INGV, Ischia is characterised by intense hydrothermal activity, documented since the early 16th century, with a close relationship between the hot-water circuits and volcano-tectonic processes: thermal waters, fumaroles and hydrothermal springs are a sign that the island's magmatic system is still active. Ischia is monitored by INGV's Vesuvius Observatory, which also carries out regular sampling of water and gases; the alert level set by the Civil Protection Department is green.

The Rotaro fumaroles are low-temperature emissions. According to the Civil Protection Department, the hottest fumaroles on Ischia, close to 100 °C, are found on the slopes of Monte Nuovo and Monte Cito and along the Maronti coast; in the island's other areas temperatures do not exceed 46 °C. The air coming out of the vents is warm or hot, and the ground around the emissions may be hot and crumbly.

A young volcano

The heat that feeds these emissions has the same origin as the volcano that hosts them. INGV describes the Rotaro as a volcanic centre built by at least nine eruptions over the last ten thousand years, including lava domes, Strombolian activity and lava flows that reached the sea. The eruptions ceased centuries ago, but the subsoil still holds heat and moving fluids.

The fumarole papyrus

Around the fumaroles grows a plant you would not expect in a Mediterranean wood: Cyperus polystachyos, known as the fumarole papyrus or, locally, “dente di cavallo” (horse's tooth). It is a species of tropical and subtropical regions, not endemic, that on Ischia finds a suitable habitat in the warm, humid microclimate of the steam emissions. As well as on the Rotaro, it is recorded in other fumarole fields on the island, such as Monte Cito and Fiaiano.

How to see them safely

• Always stay on the path: do not walk on the ground around the emissions.
• Do not put hands or objects into the steam vents, and keep children and pets close to you.
• Do not pull up plants: the fumarole papyrus is rare and lives only in these micro-habitats.
• Wear hiking shoes and bring water; there are no drinking fountains along the trails.

How to get there

Enter the Bosco della Maddalena at the Castiglione entrance, on the coastal main road, or from above, from Via Cretaio, near the Fondo d'Oglio crater. The fumaroles are along the trails linking the two entrances.