, city (1991 pop. 51,201), in Latium, W central Italy, on the Tyrrhenian Sea. The harbor, favored by Trajan (early 2d cent. ), is still the chief port of Rome. It also handles traffic for the Terni industrial area and is the main maritime link with Sardinia. Industries produce metals, machinery, chemicals, and cement. The arsenal in Civitavecchia was built by Bernini, and Michelangelo directed the final stages of the construction of the powerful citadel (begun 1508, nearly destroyed in World War II).