The story of the trulli is a very Italian story.
Italy is, regretfully, worldwide known, beside for its history, art and culture, for its tax evasion. The story of the trulli is a story of tax evasion.
They say that in the middle age the farmers of the area, in order not to pay the taxes on property (the equivalent of the ICI, or, now, IMU) created these dry-stone constructions, so that they could immediately dismantle them in a pile of stones when the king’s tax inspectors were visiting the area, proving that they did not own houses.
According to the legend, the roofs were built in a conical shape so that they can be rapidly dismantled by removing one single stone.
Brilliant, isn’t it?