The architectural landscape of Santorini is unique. Underground buildings such as houses, churches, canaves and warehouses are the traditional buildings of the island. They are the ones that characterize the unique beauty of the island despite the unrealistic architecture.
Because of it's geographic position Santorini always used to be an important center of shipping within the Mediteranean. Until the beginning of the 20th century there even was a wharf in the bay of Armeni underneath Oia with a fleet of approx. 130 sailing boats, traveling and trading. This is why shipowners and their crews used to live in this area. For the crew members who mostly because of poverty where not able to build their houses on top of the hill the peculiarity of the volcanic terrain of Santorini offered a much cheeper alternative: it allowed the inhabitants to carve most of a building or even the entire one in the earth.
The caves were the small and poor homes of Santorini, where the crews of the ships and the poorer families lived, as opposed to the two-story neo-classical mansions built by the wealthy ship owners. They were cave-like residences, oblong, carved into the Theraic earth, without foundations, with a vaulted ceiling and a narrow façade. Theraic earth is an excellent building material. It was mixed with lime stone, which was found at Profitis Elias mountain, and formed a powerful plaster which solidifies with humidity and in time becomes even harder. The layer of Theraic earth also contains pumice, a very porous, froth-like igneous rock and a bad conductor of heat and sound, so the Santorini cave houses are kept warm in the winter and cool in the summer. Important is they show great resistance to earthquakes.
The traditional cave houses usually consisted of only one room.
The cooking place was outside to prevent the smoke disturbance. Also called firecrackers it was made up of two stones inbetween which the wood was lit to heat the cooking cauldron.
The toilet was normally in a separate room outside the house and it was raised, reachable over some steps. In the empty space created underneath, the sewage was collected and transported to the fields used as fertilizer.
The only source of water was the "cistern", where the rainwater that fell into the yard or the roof and passed through the gutters was collected. As a filter, they used small sticks tied in a bunch which were placed in the gutters.
Also interesting are the other elements of the construction, such as carved recesses, built furniture, stairs, ovens, chimneys and flower beds in the yards.
Most of these cave houses along the cliffs of the caldera are todays accommodation for the numerous tourists visiting this stunning island. The former houses of the poorest of the poor turned into traditional yet modernized villas and suites because their view is of great value today.