A trullo (plural, trulli) is a traditional dry stone hut with a conical roof. When we visited Alberobello area of Italy we saw a town with a large number of these houses. Trulli were generally constructed as temporary field shelters and storehouses or as permanent dwellings by small proprietors or agricultural laborers.
There are many theories behind the origin of the design. One of the more popular theories, and the one we heard from our tour guide, is due to high taxation on property, the people of Apulia built dry stone wall constructions so that they could be dismantled quickly when tax inspectors were in the area. Of course, things have changed and these houses are now permanent structures and Alberobello has a large area of these houses and even churches having similar features.