properties, and the base beams simply sit upon stone piles such that nothing is actually secured to the ground (that is, no concrete or planting of beams). Inside, the center point of the home is the approximately one meter square irori (囲炉裏 sunken floor hearth) which would usually stay alight with low embers at all times. To maintain the burn, four chestnut logs would be placed inward at each corner and a small, flameless charcoal fire within the joining point at the center would slowly burn on the tips of the logs, and as the logs burned out they would be pushed slightly more into the center. The irori would be used for cooking, either with an iron pot stand or with the suspended jizai-kagi (自在鈎) which consists of an adjustable hook connected to a ceiling beam above and from which a pot could be hung, with the height adjusted according to the temperature sought. Often the jizai-kagi would be made of a bamboo pole with a carved wooden fish used for the hook adjusting mechanism (with the fish serving as a water talisman to ward off the danger of fire). As the fire would constantly burn, and since there are no chimneys, the ceilings and beams in these homes have now become blackened with soot, particularly the higher in the house they are. The internal bamboo lattice to which the roof thatch would be lashed to would accordingly turn a deep red-brown when polished (called susutake 煤竹), and it was sought after by handicraft workers whenever a roof was replaced. One of the main reasons to have such a smokey atmosphere was to help dry out the roof thatch from the inside and extend its lifespan (usually about 25 or 30 years). However the smoke-filled homes did serve an additional purpose, which was to help cure the tobacco leaves that would be hung from the rafters during the winter (until the 1970s, tobacco was the primary cash-crop in the valley. Currently it is no longer grown anywhere in Iya). Also standard in the homes is the storage cellar, located under a removable pair of floor boards. This cellar would be dug about one meter deep into the ground and would be used to store potatoes, pickles and other foods as the temperature would be cooler and more consistent down there in the summer. The best known historical houses of