The term trullo (of uncertain etymology) derives from the latin turris or trulla or from the greek tholos, all terms that means cupola.
The trulli are usually characterized by a quadrangular base (with walls that go from a thickness of 80 cm until 270 cm of the Trullo Sovrano), covered from cone and realized with dry stones without use of mortar.
It’s a very particular architectonic kind: resumptions of technologies coming from ancient times (Greek, Sardinian “nuraghe”, Micenee tombs), by the other hand they used constructive techniques diffused in a particular historical period, ranging from the second decade of the XVIIth and the end of the XVIIIth century (easy way of pulling down the constructions to avoid regal inspections).

The trulli have on their top decorated elements that close the cone: the pinnacoli.
They are usually carved in stone and represent the signature of the Master “trullaro” building up the trullo.