Around 1600 BCE the Minoan eruption threw an estimated sixty cubic kilometres of magma into the sky and emptied the chamber beneath the island; the volcano's roof then fell into the sea.
What remains is the Santorini caldera — a flooded crater roughly twelve kilometres across, with water more than three hundred metres deep in places. Cliffs of pumice and red scoria rise a further three hundred metres above the surface. A santorini catamaran tour from cruise port therefore begins inside a collapsed mountain, not beside one.
Fira Old Port sits at the base of that wall, at Fira 847 00, a thin strip of quay with no road connection to the town above. Access is by 588 steps cut in switchbacks through the scoria, by mule along the same path, or by the cable car funded by the Nomikos family and opened in 1979. Passengers holding santorini catamaran tour from cruise port tickets descend the same cliff face that cargo crews worked for most of the twentieth century, before the island's freight and ferry traffic shifted south to Athinios. The port charges nothing to enter; it was never a town, only a landing.
The water beyond it is the reason the harbour still matters. Two dark islets, Palea Kameni and Nea Kameni, sit at the caldera's centre. They are the volcano's newest work, raised by eruptions recorded from 197 BCE onward, with Nea Kameni emerging between 1707 and 1711 and venting for the last time in 1950. Iron-rich springs stain the shallows off Palea Kameni a rust orange. Across the basin, Thirassia was severed from the main island by the same collapse, and Aspronisi survives as a sliver of white ash.
Caldera sailing trips trace this geology directly. The southern coast, outside the crater rim, holds Red Beach beneath its oxidised cliff and White Beach under pale tuff — both effectively reachable only from the water. Catamarans, shallow-drafted and stable under sail, work these coves where deeper hulls cannot. Travellers weighing santorini catamaran tour from cruise port tours are, in practice, choosing between routes across a drowned volcano: the Kameni craters, the sulphur-warmed shallows, the western rim where the terraces of Oia hold the last light. Santorini Caldera is not scenery arranged around a harbour. It is the harbour's cause.
5 hr
