The gap between the two skins is filled with
rubble. The trulli's conical roof is normally capped with a
hand-worked sandstone pinnacle which can be a disk, a ball, a cone
or other geometric designs that represent the signature of the stonemason.
The roof itself may have a design painted on it in lime
representing religious figures like Santa Maria Addolorata denoted by a pierced heart. Trulli were first built in the 16th century by
farmers forced to settle on the poor, stone ladened land. There
are about 1,600 trulli in the region. Their thick walls provide
cool shelter in the hot summers and insulation in the winter
maintaining a comfortable living space.