Ariano Di Puglia, a town and episcopal see, which, despite its name, now belongs to Campania, Italy, in the province of Avellino, 1509 ft. above sea-level, on the railway between Benevento and Foggia, 24 m. E. of the former by rail. Pop. (1901) town, 8384; commune, 17,653. It lies in the centre of a fertile district, but has no buildings of importance, as it has often been devastated by earthquakes. A considerable part of the population still dwells in caves. It has been supposed to occupy the site of Aequum Tuticum, an ancient Samnite town, which became a post-station on the Via Traiana1 in Roman times; but this should probably be sought at S. Eleuterio 5½ m. north. It was a military position of some importance in the middle ages. Thirteen miles south-south-east is the Sorgente Mefita, identical with the pools of Ampsanctus (q.v.).
1 This has generally been supposed to be the place referred to by Horace (Sat. i. 5. 87), as one which the metre would not allow him to mention by name; but H.-Nissen (Halische Landeskunde, Berlin, 1902, ii. 845) proposes Ausculum instead.
