Situated on the heights of the hill are the ruins of the Castle, dating from the
medieval period and restored first by Giovanna I, then by the Aragonese and,
finally, by Charles V. The castle walls join up with those of the historical centre, which preserves steep streets, lanes and characteristic corners.
Again in the upper part of the town, one can find the ruins of the church of St. Francis of Assisi and the adjoining convent, both dating from the 13th-14th century.
In the lower part of the town one can visit the ruins of the ancient walls and the interesting church of St. Bernardine of Siena, dating from the 15th century, whose facade is decorated with majolica coated bowes and plates, nearly all of the 15th century and the only example of this type of decoration in southern Italy.