The Church, Convent and Cloisters of San Sebastian was erected in 1474, together with the convent of the Minori Osservanti monks, with the help of Duke Ferdinando II Orsini, over the ruins of a Benedictine abbey and of a neighbouring church, dedicated to Santa Maria della Pace, from which it initially took its name. This name was changed in 1483 to San Sebastian, when the population attributed their salvation from a recent plague to the saint. The interior of the church has a nave and 2 side aisles.
The painting of San Sebastian, by Fra Giuseppe da Gravina is among the most interesting works inside the church.  The cloister consists of arches and columns supporting the convent portico and the first floor rooms, with an ancient well in the centre. Here we find a precious cycle of 17th century frescoes by Fra Giuseppe da Gravina.
The so-called “Fèst’ d’ Crist”, the second religious “feast” held in the city and a famous local event, is celebrated on the last Sunday in May or the first Sunday in June, with a procession that recalls the ancient processions to mark the period of reaping and harvesting.