Top 10 Volcanoes in Greece
Greece sits above the slow grind of the African Plate beneath Eurasia, and the Hellenic Volcanic Arc curves through the southern Aegean. It is a quiet arc by world standards — but Santorini's bronze-age eruption was one of the largest in the last 10,000 years, and Nisyros is still restless.
1. Santorini (Thera)
The most famous Greek volcano, with a flooded caldera and a long history of explosive eruptions. The Minoan eruption around 1600 BCE buried Akrotiri and reshaped the Aegean. Today's vivid white cliffs of Oia are the eroded inner rim.
2. Nea Kameni (inside Santorini caldera)
The young lava island inside the Santorini caldera, built by eruptions from 1707 to 1950. The boat trip from Fira lands you in fresh-looking black pumice and steaming vents.
3. Nisyros
A near-perfect caldera island in the Dodecanese, with the Stefanos crater on the floor — a hot, sulphur-fumed pit you can walk into. Last explosive activity in 1888.
4. Milos
An older volcanic island still mined for industrial minerals. The bright sulphur-yellow and ochre cliffs of the south coast are visible volcanic chemistry. The beaches at Sarakiniko look like sculpted moon landscape.
5. Kos
The eastern flank of Nisyros's caldera is preserved as part of Kos island. The 161 ka Kos eruption was one of the largest in the Mediterranean — its pumice deposits reach across hundreds of kilometres.
6. Methana
A small peninsula in the northern Saronic Gulf with Holocene cones and hot springs. Local thermal baths and a few accessible cinder cones.
7. Sousaki
Near the Corinth Canal, with active fumaroles and surface sulphur. The only volcanic centre on the Greek mainland.
8. Aegina
A small island in the Saronic Gulf, with a 2-million-year-old volcanic core preserved at its centre. Famous more for pistachios than eruptions, but the bedrock is volcanic.
9. Poros
Adjacent to Methana, with related volcanic rocks visible on the island. Geologically part of the same Saronic Gulf system.
10. Yali
A small uninhabited island near Nisyros — essentially a pumice quarry on volcanic substrate. Reminder of how much pumice the arc has produced.
Why the arc exists
The African Plate is being subducted northwards beneath the Aegean. As the slab descends, water released from it lowers the melting temperature of the overlying mantle, generating arc magma. Santorini and Nisyros sit roughly 150 km above the slab.
Safety and access
Nisyros's crater can be walked into but the floor is fragile and the fumaroles are deadly without ventilation. Nea Kameni is visited by boat tour with mandatory walking guides in summer. Always check the Greek Geophysical Survey for current advisories.
On the map
Open the map and filter to Greece to see the arc curving through the south Aegean from Methana to Nisyros — a slow, beautiful chain hiding more power than its tourist face suggests.