The Volcano

Volcanism on Santorini is due to the Hellenic Trench subduction zone southwest of Crete. The oceanic crust of the northern margin of the African Plate is being subducted under Greece and the Aegean Sea, which is thinned continental crust. The subduction compels the formation of the Hellenic arc, which includes Santorini and other volcanic centers, such as Methana, Milos, and Kos.

The island is the result of repeated sequences of shield volcano construction followed by caldera collapse. The inner coast around the caldera is a sheer precipice of more than 300 meters (980 ft) drop at its highest and exhibits the various layers of solidified lava on top of each other and the main towns perched on the crest. The ground then slopes outwards and downwards towards the outer perimeter, and the outer beaches are smooth and shallow. Beach sand color depends on which geological layer is exposed; there are beaches with sand or pebbles made of solidified lava of various colors: such as the Red Beach, the Black Beach and the White Beach. The water at the darker colored beaches is significantly warmer because the lava acts as a heat absorber.

The area of Santorini incorporates a group of islands created by volcanoes, spanning across Thera, Thirasia, Aspronisi, Palea, and Nea Kameni.

Santorini has erupted many times, with varying degrees of explosivity. There have been at least twelve massive explosive eruptions, of which at least four were caldera-forming. The most famous eruption is the Minoan eruption, detailed below. Eruptive products range from basalt all the way to rhyolite, and the rhyolitic products are associated with the most explosive eruptions.

The earliest eruptions, many of which were undersea, were on the Akrotiri Peninsula, and active between 650,000 and 550,000 years ago. These are geochemically distinct from the later volcanism, as they contain amphiboles.

Over the past 360,000 years, there have been two major cycles, each culminating with two caldera-forming eruptions. The cycles end when the magma evolves to a rhyolitic composition, causing the most explosive eruptions. In between the caldera-forming eruptions are a series of sub-cycles. Lava flows and small explosive eruptions build up cones, which are thought to impede the flow of magma to the surface. This allows the formation of large magma chambers, in which the magma can evolve to more silicic compositions. Once this happens, a massive explosive eruption destroys the cone. The Kameni islands in the center of the lagoon are the most recent example of a cone built by this volcano, with much of them hidden beneath the water.

Volcanic craters and hot springs are present on both islands. Dormant Craters and active vents can be visited on Nea Kameni. Both volcanic isles are under scrutiny by satellite as well as underground systems. Even the minutest alteration is recorded to forecast any hint of reactivation.


As part of the Aegean style, traditional Santorini architecture exhibits an unusual freedom of expression as it incorporates the particularities of the island into the structured environment. The peculiarity of the ground allows for the creation of subterranean buildings under cultivated fields, buildings so closely connected to each other that you cannot tell where one property ends and where the other begins…
M. Danezis, 1939, “The Theraic Common Law in the 18th century”.

The essential factor in the creation of the built-up space on the island from the Middle Ages until the late 18th century had always been that of safety. Living under circumstances of turmoil and being exposed to pirate raids, the inhabitants were forced to an incessant defensive struggle. Therefore, architecture ought to have had a defensive character, that is to provide security above all.

More or less, it used to serve only essential needs. Far from setting off any stylistic elements, it derived from the particular manner of development and the structures themselves. This particular architectural morphology owes its existence to exclusively local factors: Social, financial, structural and geomorphological ones. Commercial sources were limited, homes were built by unskilled workers (usually the owners themselves). Dwellings were cut in the volcanic lava in an attempt to cover life’s needs in an improvised manner lacking any intention of differentiation.

As time passed, especially from the end of the 18th century onwards, survival demands had been overcome by certain population groups, and it was time for the architectural forms to serve other purposes. Lords and people well-to-do could lead a much more comfortable life, but they could do it only in a large, comfortable and richly decorated home.

Considering mansions, the architecture of 18th and 19th centuries witnessed the artistic intervened of masters and reflected the models of a great art either indirect or applied imitation according to local singularities. They took advantage of the influences of western or post-renaissance models, not by imitating them but by readjusting them to a simplified local variation that could make use of the structural factors of the place. Classicism and its various forms came to be applied rather late, towards the end of the 19th century, mainly to the mansions of the wealthy, the big churches and public buildings (Museum, schools, etc.).

Even in those buildings that imitated official architecture produced an extremely successful result. The co-existence of vernacular together with those of official architecture within the settlements produced a fascinating effect but also fulfilled the novel requirements of the Theran society and the human needs.

Main types of Settlements & houses

Village settlements fell into three categories:

  • Linear (Fira, Oia, Therassia)
  • Evolved fortified (Pyrgos, Emporeio, Akrotiri village)
  • Rock-hewn (Vothonas, Foinikia, Karterados).

As far as their construction is concerned, buildings could be

  • Rock-hewn (underground)
  • Built
  • Semi-built

Types of houses were distinguished in:


In Santorini, the original type of residence was like the one found inside the Kastelia. The one-room houses were either stone-built or rock-hewn, usually two-story, due to limited space, and narrow-fronted. An external staircase led to the upper floor. The ground floor accommodated auxiliary spaces, such as stables and storage areas. The homes of the nobles inside the castles probably followed the same rationale, only on a larger scale. When settlements expanded beyond the defensive perimeters, auxiliary buildings were added to the main construction, adjacent or connected to it through the yard, where a significant part of daily activities took place. Urban houses maintained their irregular shapes.
Rural houses had a big yard and auxiliary buildings (an outdoor, usually cylindrical, brick oven, stables, etc.). They were located in the countryside or on the village outskirts. Most of them also had kanaves (wineries).


A few homes from that time survive in all villages. Residential complexes can be found in neighborhoods such as Sideras in Oia, Frangomahalas in Fira, and at the center of Mesaria (see also The Unknown Santorini and Attractions sections). Their foreign influences – Renaissance or Neoclassical or both – are distinct, as their owners had various contacts abroad. They are very imposing, with symmetrical, monumental fronts.


These were built by non-experts to cover housing needs; however, they turned out to be artistic works of unique aesthetics. They are the most numerous on the island, mainly characterized by plasticity and simplicity. An interesting fact is that they overlap; they also have domes of different shapes and sizes, and their outdoor spaces are irregularly shaped. Fronts have small openings, windows, and doors with lunettes. This type of house was an inspiration for architects of the early 20th century, such as Le Corbusier, Alvar Aalto and others.


Built by craftsmen, they were bigger and more complex than the folk architecture houses. Most urban houses and churches are typical examples of this category.


Local specialties you need to try:

  • Brantada – A local Santorinian fish dish. Cod fillet coated in a mixture of flour, water, salt and sometimes beer, commonly served with garlic salad. The best place to try it is in some less touristic villages, like Exo Gonia.
  • Koskosela (local Strapatsada)
  • Santorinio Sfougato – A traditional Santorini dish. Ingredients: small zucchini, onions, extra virgin olive oil, flour, eggs, rosemary leaves or spearmint tea leaves or dill, xynomyzithra or other sour milk cheese or soft feta, Naxos sweet gruyère, salt and fresh ground pepper, sweet peppers, sesame seeds.
  • Tsounisti (Manestra)
  • Fava – A local Santorini dish, originally made with the broad bean. Later on, the broad bean was replaced with an easier version; the yellow shelled lentil. Its name originates from the word “favus” which is the Latin word for broad beans.
  • Melitinia (dessert) – Melitinia is cookies that are made for weddings, engagements, and festivals. They are made of unsalted mizithra cheese and yogurt, and they also have a beautiful smell of mastic. They can be found in the traditional bakeries of Santorini.

Wine industry

The island remains the home of a small, but flourishing, wine industry, based on the indigenous grape variety, Assyrtiko, with auxiliary cultivations of two other Aegean varietals, Athiri and Aidani. The vines are extremely old and resistant to phylloxera (attributed by local winemakers to the well-drained volcanic soil and its chemistry), so the vines needed no replacement during the great phylloxera epidemic of the late 19th century. In their adaptation to their habitat, such vines are planted far apart, as their principal source of moisture is dew, and they often are trained in the shape of low-spiraling baskets, with the grapes hanging inside to protect them from the winds.

The viticultural pride of the island is the sweet and strong Vinsanto (Italian: “holy wine”), a dessert wine made from the best sun-dried Assyrtiko, Athiri, and Aidani grapes, and undergoing extended barrel aging (up to twenty or twenty-five years for the top cuvées). It matures to a sweet, dark amber-orange, an unctuous dessert wine that has achieved worldwide fame, possessing the standard Assyrtiko aromas of citrus and minerals, layered with overtones of nuts, raisins, figs, honey, and tea.

White wines from the island are extra dry with a strong, citrus scent and mineral and iodide salt aromas contributed by the ashy volcanic soil, whereas barrel aging gives to some of the white wines a slight frankincense aroma, much like Vinsanto. It is not easy to be a winegrower in Santorini; the hot and dry conditions give the soil a very low productivity. The yield per acre is only 10 to 20% of the yields that are common in France or California. The island’s wines are standardized and protected by the “Vinsanto” and “Santorini” OPAP designations of origin.