Italy's cone-roofed trulli were built without a drop of mortar
The white huts with stone cones that crowd the Apulian town of Alberobello are held together by nothing but careful stacking. A popular story says peasants built them without mortar so they could be dismantled before the tax inspector arrived. Whatever the truth, each dome is two layers of dry limestone that still keeps out the rain.
Trulli belong to the Itria Valley in the Murge, a limestone plateau in Italy's heel where rain vanishes into underground channels and there are no permanent streams. That scarcity shaped the building method. Construction began by digging a cistern to store water, and the stone quarried from that pit supplied the walls, which rest directly on bedrock and can be up to 2.7 metres thick. The roof is an inner shell of wedge-shaped stones closed by a keystone, covered by an outer skin of slabs tilted slightly outwards to shed water. Roof stones can even be lifted off without destabilising the rest.
Most trulli have one room beneath each cone, so a larger home is a cluster of cones, with children often sleeping in curtained alcoves cut into the walls. The thick stone keeps interiors cool in summer, but in winter they turn cold and damp, hard to warm even beside the fire, so families traditionally lived largely outdoors. A carved sandstone pinnacle crowns many cones, said to be the builder's signature, and some cones bear painted symbols; many of those were added only in recent decades during renovation.
Alberobello itself is younger than it looks. Records describe the area mostly as forest until a map from 1704 shows a small nucleus of trulli in a woodland clearing, the settlement named for a beautiful tree. The golden age came in the 19th century, especially its final decades with the spread of vineyards. When labour costs rose in the 20th century, moving hundreds of tonnes of stone for one house became unaffordable, and rural building stopped.
Today the trulli are protected as a UNESCO World Heritage Site and popular with British and German buyers. Restoration is strictly regulated and pricey: rebuilding a roof cost about 1,500 euros in 1999 and roughly 15,000 euros by 2009.
Source: Trullo
