Alberobello, the city ofdrystonedwellings known astrulli, is an exceptional example of vernacular architecture. It is one of the best preserved and most homogeneous urban areas of this type in Europe. Its special features, and the fact that the buildings are still occupied, make it unique. It also represents a remarkable survival of prehistoric building techniques.

There was prehistoric settlement in theItriaand thetholos(dome-shaped tomb) tradition of building may have come to the region at this time. The present settlement dates from themid-14thcentury.... Tradition has it thatdrystone(without mortar) walling was imposed upon the new settlers so their houses could be quickly dismantled. This served two purposes: recalcitrant householders could be dispossessed easily and, later, it would be possible to avoid taxation on new settlements.

These buildings were constructed using roughly worked limestone boulders collected from neighboring fields and, later, the large water-collecting basins in the area. They were built directly on the underlying natural rock, using exclusively thedrystonetechnique. The walls that form the rectangular rooms are double, with rubble cores, and are pierced by small windows.

The interiors are equipped with wooden fittings, such as door frames, barrel-vaulted niches, etc., and in some of the largertrullithere is a second story formed from a wooden floor and reached by means of a wooden staircase. Stone fireplaces and ovens are ventilated through stone slabs covering them. The roofs are not painted and develop a patina of mosses and lichens; they sometimes bear mythological or religious symbols in white ash.