In the north east of Iran on the border with Azerbaijan is a mountainous province, called…. Azarbayjan. At the foot of Mount Sahand in Kandovan, the villagers live in cave homes carved out from the volcanic rock.
The houses are of two to four storeys; the ground floor is used for animals, the first and maybe second floor as well, are used as living areas, whilst the top floor is used to store things.

Most houses face south so residents enjoy sunlight during the day. The houses have windows with decorative glass. It is said that the houses have an “air circulation system that keeps the homes cool in summer and warm in winter”, but I suspect it is the great thermal capacity of the whole mountain rock that is doing the work. Nowadays the houses have electrical connection, water piped in and even waste plumbing.
The Sahand is well known for its spring-water which is believed to be able to cure diseases. A river runs through the valley in the village, providing water for the agricultural terraces and animal husbandry.

Source: weblog.shaar.com