Nea Kameni: Santorini’s Volcanic Caldera and a Landscape Still Forming

Nea Kameni, “the New Burnt Island”, is the young volcanic island at the centre of Santorini’s flooded caldera, a dark mound of lava about two kilometres across that has grown out of the sea through a series of eruptions over the last few centuries, most recently in 1950. Its paths lead across black, jagged lava flows to craters where warm gases still rise from the ground. From the cliffs of Fira and Oia it looks like a scorched shadow in the middle of the bay; walking on it, you are standing on the part of Santorini that is still being made. On our Santorini, Crete, Rhodes and Cyprus tour we take an excursion to Nea Kameni on Day 4, the day after visiting Akrotiri and Ancient Thera.

The caldera as a layered landscape

To understand Nea Kameni, start with the bay it sits in. Santorini’s caldera is a great basin roughly 12 kilometres long and 7 kilometres wide, enclosed on three sides by cliffs about 300 metres high and flooded by the sea to depths of nearly 400 metres. It is not the work of a single eruption. The island is the remnant of a volcanic complex built up over hundreds of thousands of years from overlapping volcanoes, and geologists have identified at least four calderas, each formed when the ground collapsed into an emptied magma chamber after a major eruption. The present basin took its shape in the Late Bronze Age eruption that buried the town of Akrotiri, about 3,600 years ago.

The cliffs are a record of that history. From a boat in the middle of the bay, you can see them banded in red, black, grey and cream: lava flows, layers of ash, and, near the top, the thick pale deposits of pumice from the Bronze Age eruption. The villages of Fira, Imerovigli and Oia are built along the rim, on top of the very layers that tell the story of the volcano beneath them.

How Nea Kameni was formed

After the Bronze Age eruption, the volcano did not fall silent. Over the following centuries, smaller eruptions began to build new land in the centre of the flooded caldera. Roman writers recorded a new islet appearing there in the first century AD, and the smaller island of Palea Kameni, “the Old Burnt Island”, grew from eruptions beginning in Roman times, including one in 726 that also covered the city of Ancient Thera in pumice.

Nea Kameni is younger still. Its oldest exposed parts date from an eruption around 1570, and the island has grown through a sequence of eruptions since: 1707 to 1712, 1866 to 1870, 1925 to 1928, and 1939 to 1941, with the last, a small extrusion of lava, in 1950. Each eruption pushed out thick, slow-moving lava that piled up into domes and flows rather than running far, which is why the island is so rough and blocky. Today Nea Kameni covers about 3.4 square kilometres and rises only a little over a hundred metres above the sea.

The craters are named after the eruptions that formed them. The most visited is the crater of King George I, named for the Greek king of the 1860s, which formed in 1940 when steam explosions blew open the top of the dome built in 1866. Around its eastern rim, hot gases at around 75 to 95 °C still seep out of the ground, and the smell of sulphur hangs in the air.

What a walk on Nea Kameni reveals

The island is a place to read the ground. As the path climbs from the landing, notice the difference between the older, weathered lava, where lichens and a few hardy plants have taken hold, and the younger flows of the twentieth century, still black, sharp and almost bare. Look at how the flows end in steep, rubbly fronts rather than thin sheets: this is the behaviour of thick, sticky lava, which builds up around its vent rather than travelling far.

Near the craters, the ground changes again. Yellow and white crusts of minerals mark the places where volcanic gases reach the surface, and the warm, sulphur-scented air is a reminder that the system beneath is not extinct. From the summit, the view takes in the whole caldera: the cliffs and villages around the rim, the smaller dark island of Palea Kameni, and, on a clear day, the outline of the volcanic complex as a whole, with the inhabited rim, the flooded centre and the young islands within it. Nowhere else on Santorini makes the shape of the volcano so easy to see.

Palea Kameni and the warm springs

Nea Kameni has a smaller, older neighbour. Palea Kameni, a short distance to the south-west, is about half a square kilometre in area and was built up by eruptions from Roman times onward. Around its shores, volcanic hydrothermal activity warms the sea in places and stains it a rusty orange-brown with iron. Many boat excursions in the caldera stop nearby so that passengers can swim in the warmer water. It is an open-water swim in the sea, not a spa: the temperature varies, the water is deep, and the stop depends on the wind and the state of the sea. For those who prefer to stay on board, the colour of the water against the black rock is itself an easy lesson in how heat and minerals move through the volcano.

Why Nea Kameni is protected

Because it is so young, and its eruptions so well recorded, Nea Kameni is one of the clearest examples anywhere of a volcanic island in the making. The Greek Ministry of Culture has designated it a historic place of exceptional natural beauty, and it is regarded as a monument of major scientific interest, visited by geologists as well as travellers. The island is managed as a geological park, with a marked route and set stopping points around the craters, and visitors are expected to keep to the paths and leave the rocks and minerals where they lie. Treading carefully here protects a landscape whose details, from the shapes of the lava flows to the mineral crusts at the vents, are still part of an active scientific record.

Living with a volcano

People have lived on Santorini for thousands of years with the volcano as a neighbour, and the island’s history is shaped by it at every stage. The Bronze Age town of Akrotiri was abandoned and buried by the great eruption of the seventeenth or sixteenth century BC; its people appear to have left after warning earthquakes, before the eruption itself. Ancient Thera, on the mountain ridge in the south-east, was eventually abandoned after the eruption of 726. In modern times, eruptions on the Kameni islands have been watched from the cliffs by islanders and visitors alike.

The volcano is closely monitored today by Greek scientific institutions, using networks of seismometers, satellite measurements of ground movement and regular measurements of volcanic gases. Periods of unrest, including ground deformation in 2011 and 2012 and a prolonged sequence of earthquakes in 2025, have been followed by careful scientific assessment, and the Greek civil protection authorities set the rules for access to particular areas based on that advice. For travellers, the practical point is a simple one: the volcano is studied continuously, and visits take place within the arrangements the authorities set at the time.

How much walking does Nea Kameni involve?

A moderate amount, on rough ground with no shade. From the landing, a gravel and rock path climbs gradually to the crater area, and a typical visit on the island takes about an hour and a half. The surface is uneven and loose in places, and the dark lava absorbs the sun, so sturdy, closed shoes, a hat, sun protection and water are essential. There are no facilities on the island itself. The tour as a whole is rated Level 2, Moderate: three to five hours of activity a day, the equivalent of walking up to eight kilometres on uneven ground.

Is it safe to visit Nea Kameni?

Visits take place under the supervision of the Greek authorities, who monitor the volcano and can restrict access to particular areas of Santorini on scientific advice; such restrictions have applied to some parts of the island in 2025 and 2026. Visitors are expected to keep to the marked paths and the permitted viewing points around the craters. We confirm the arrangements for the excursion before each departure, and if access to Nea Kameni is not possible on the day, the programme may need to change.

From geology to culture

Nea Kameni brings together the story the tour tells on Santorini. The volcano created the island’s landscape, buried its Bronze Age town and later shaped where people chose to build. It also shaped how they farm. The same afternoon, we visit a winery to see how Santorini’s growers have adapted to volcanic soil, wind and drought, training their vines into low baskets on the ground; our article on Assyrtiko and Santorini’s basket-trained vines explains the practice. For the wider history of the island, from first settlement to the present, see our history of Santorini, and for how Santorini fits into the whole journey through Crete, Rhodes and Cyprus, our Eastern Mediterranean islands itinerary.

Few places let you stand on land younger than many of the buildings in Europe’s old cities. On Nea Kameni, with warm gas seeping from the rocks and the caldera cliffs all around, Santorini’s long volcanic story stops being something in a museum and becomes the ground under your feet. To see it with a guide, in a small group of 6 to 14 travellers, explore the Santorini, Crete, Rhodes and Cyprus small group tour.