It is a typical medieval centre, developed around a small agglomeration located on top of the hill and dating back to the Roman period. Subsequently, the town extended further down through an intrigue of small open spaces and winding stairways. 
Most of the houses and streets are made of stone.
Exciting is the crypt discovered only in 1928 and which represents one of the first early Christian oratories of the 4th century, probably built on an area dedicated to the goddess Diana. 
It is divided into three transverse aisles by seven longitudinal ones, with pillars supporting round arches and small cross vaults. 
On the altar is a stone lunette, a low relief represents the SS. Trinity flanked by two angels, two dolphins and across. On the walls, there are two frescoes still visible.