Key of the trullo.
Or simply pinnacolo.
Every trullo, whatever its size, always ends with a pinnacle or a cuspidate element that closes the cone.
The cone is generally composed of four parts:
1) the last rows of whitewashed chiancarelle;
2) the cannarile, with a cylindrical or truncated cone shape;
3) the carrozzella or scodella on which the fourth element rests;
4) the cocla, carved from a single piece of stone.
As for the symbols drawn on the cones, the pinnacle is for many an element not only decorative but also and above all religious/pagan. A link between heaven and earth, between sacred and profane, the pinnacle would suggest a reproduction of the cosmic forces that interact with the earth.
Other theses, instead, sustain that the pinnacle represents the stylistic code, a sort of sculptural signature, of the master trullaro; finally, the most, connect it to a distinctive element of the families that belonged to the same stock and that used the same distinctive symbol on their houses.
The most known pinnacle has a spherical or disc shape, but there are also pinnacles with more complex shapes, such as a polyhedron with a cross or star or cone.
Whatever the shape or size, the pinnacles present on all Trulli represent, despite the passage of centuries, a boast of beauty and uniqueness.