CASTELLAMMARE DI STABIA, a seaport and episcopal see of Campania, Italy, in the province of Naples, 17m. S.E. by rail from the town of Naples. Pop. (1931) town, 34,553; com mune, 43,713. It lies in the south-east angle of the bay of Naples. at the beginning of the peninsula of Sorrento, and owing to the sea and mineral water baths (12 different springs) and its attrac tive situation, with a splendid view of Vesuvius and fine woods on the hills behind, it is a favourite resort of Neapolitans in summer. The ruined castle from which it takes its name, on the hill to the south of the town, was built by the emperor Frederick II. There is a large royal dockyard (3,00o workmen), and a small-arms fac tory; there are also ironworks, cotton, flour and macaroni mills. An electric tramway leads along the coast to Sorrento.