What Is Therasia Known For?

Therasia forms one half of the same volcano that gave Santorini its shape, and a single ancient olive shrub discovered on the island recently helped scientists pin down exactly when that eruption happened.

Therasia is known first for its role in the Santorini caldera, since the island and Santorini together represent the surviving outer rim of a volcano that collapsed during the Minoan eruption, one of the most powerful volcanic events ever recorded, generally dated to the mid-16th century BC. Before that eruption, Therasia and Santorini formed a single, continuous landmass, and the two islands still trace the arc of that original caldera today, with a narrow channel marking where the eruption split them apart.

The island played a direct role in helping scientists date that eruption more precisely. Researchers found the remains of an ancient olive shrub buried near the Monastery of Panaghia Koimisis on Therasia's southern tip, and radiocarbon analysis of its growth rings, published in the journal Scientific Reports, helped confirm a date range for the eruption that aligns with volcanic sulfate markers recovered from ice cores elsewhere in the world, giving Therasia a genuine role in the ongoing scientific record of one of history's most significant natural disasters.

Therasia is also known as one of only two inhabited islands within the caldera itself, alongside Santorini. Manolas, the main village, keeps traditional Cycladic architecture along its narrow streets, while Potamos, a smaller settlement nearby, holds cave dwellings carved directly into the rock, a building style shared with parts of Santorini across the water. Despite its small size of just over nine square kilometers, the island holds 21 churches scattered across its landscape.

Therasia connects by ferry to Santorini, giving visitors an easy way to see the same caldera from the side most tourists never reach.