The settlements of Santorini can be distinguished in linear (Fira, Oia, Therassia), fortified (Pirgos, Emporio, Akrotiri) and vaulted ones (Vothonas, Finikia , Karterados). The buildings were vaulted, built or half built. The most famous structures of the island, the vaulted ones, are dug in the vertical layer of the so-called “aspa”, the volcanic ground of Thera. The main characteristics of these vaulted structures are the simplicity and the harmony of the volumes, as well as the fact that they “penetrate” each other. This building style influenced the architects of the early 20th century – it also influenced Le Corbusier and Alvar Aalto, among others.
In most churches of the island vernacular architecture prevails. The white-washed surfaces of various forms are impressive. These churches have no architectural adornment and a few, small openings.