town, Campania regione, southern Italy. It is situated on a rocky eminence in the Apennines, east of Benevento, in a fertile district that has often been devastated by earthquakes. There is a castle of Norman origin and a 16th-century cathedral in Ariano Irpino. Cave dwellings can still be seen in the vicinity. Cement, pottery, and textiles are manufactured locally, and gypsum mines are nearby. Pop. (2006 est.) mun., 23,297.