Modern Santorini, with its cracked crescent shape and towering caldera rim, isn't a passing geological accident — it's the direct result of one of the most violent volcanic eruptions in recorded human history.

The eruption of Thera: Around the 17th century BCE (commonly dated to roughly 1600 BCE), the island's volcano — known in antiquity as Thera — erupted with such force that scientists rank it among the highest levels on the volcanic explosivity index. The blast tore apart the island's center and sank much of it beneath the sea, leaving the distinctive crescent shape we see today — which is, in fact, the surviving rim of a giant crater partially flooded by the sea.

Akrotiri: the Pompeii of the Aegean: Before the eruption, a thriving city belonging to the Minoan civilization (centered on Crete) stood at the island's southern end, called Akrotiri. The volcanic ash that buried the city exceptionally preserved its buildings, streets, and advanced drainage systems — much as Vesuvius later did with Pompeii, centuries afterward. Ongoing excavations since the 1960s have uncovered richly detailed painted frescoes depicting sea scenes and daily life, now displayed at the Museum of Prehistoric Thera in Fira. Notably, excavations have not yet found large numbers of human remains, suggesting residents evacuated before the major eruption, likely after a series of warning tremors.

The eruption's impact on Mediterranean history: Many researchers believe this eruption and the tsunamis that followed contributed to weakening the Minoan civilization on nearby Crete, and may have later inspired Greek myths of sunken cities — though a direct link to the Atlantis legend specifically remains scientifically debated.

Santorini after the eruption: The island was gradually resettled through the Greek, Roman, and Byzantine eras, then passed under Venetian and Ottoman rule before becoming part of the modern Greek state. Volcanic activity never fully stopped; the small island of Nea Kameni at the center of the caldera remains an active volcano that can be visited on a short boat tour, and the island saw another minor eruption as recently as 1950.

Today, everything you see in Santorini — from the shape of its bay to the color of the volcanic soil its vines grow in — is the direct legacy of that ancient catastrophe that transformed an ordinary island into one of the most striking landscapes on Earth.