Santorini caldera

The Santorini caldera is the large, water-filled volcanic caldera at the centre of the Santorini island group in the southern Aegean Sea, formed by a major eruption in the Bronze Age (the Minoan eruption, around 17th century BCE). The present caldera is surrounded by steep island cliffs and contains several volcanic islets in its lagoon.

Prominent visitor experiences include boat trips to the central islets, walks and viewpoints along the caldera rim, and visits to the volcanic hot springs and the central islets. The caldera’s rim towns sit on cliffs that rise to roughly 300 metres above the sea, and the caldera itself is roughly a dozen kilometres across.

The caldera was created by a catastrophic eruption in the Late Bronze Age that reshaped the island group and submerged the central volcano, leaving the current ring of islands. Subsequent eruptions have produced the smaller volcanic islets that sit in the caldera today.

Geographically the caldera lies in the Cyclades of the South Aegean region of Greece, with the main inhabited island of Santorini (Thira) forming the largest portion of the rim. It is reached by ferry and air services from mainland Greece and nearby islands.

• Caldera rim: Cliff tops around the caldera reach up to about 300 metres above sea level, offering panoramic views; boat trips to the caldera and hot springs are common day excursions.

What to See #

• Nea Kameni: A volcanic islet formed by repeated eruptions; central islands host active fumaroles and are regularly visited by boat tours from Santorini's ports.
• Palea Kameni: A smaller volcanic islet near Nea Kameni with historical lava deposits and nearby hot springs used for short tourist visits.
• Caldera rim towns: Cliff-top settlements perched on the caldera rim, notably the towns known for cliff viewpoints and sunset views.