A trullo (plural, trulli) is a traditional Apulian stone dwelling with a conical roof. The style of construction is specific to the Murge area of the Italian region of Apulia (in Italian Puglia). They may be found in the towns of Alberobello, Locorotondo, Fasano, Cisternino and Martina Franca.
Trulli were generally constructed as dwellings or storehouses. Traditionally they were built without any cement or mortar. This style of construction is also prevalent in the surrounding countryside where most of the fields are separated by dry-stone walls.
The roofs are constructed in two layers: an inner layer of limestone boulders, capped by a keystone, and an outer layer of limestone slabs ensuring that the structure is watertight. Originally, the conical structure would have been built directly on the ground, but most of the surviving structures are based on perimeter walls.
The walls are very thick, providing a cool environment in hot weather and insulating against the cold in the winter. The vast majority of trulli have one room under each conical roof: a multiroomed trullo house has many cones representing a room each. Children would sleep in alcoves made in the wall with curtains hung in front.