Miseno is one of the frazioni of the municipality of Bacoli in the Italian Province of Naples. Known in ancient times as Misenum, it is the site of an ancient port in Campania, in southern Italy.
Nearby Cape Miseno marks the northwestern end of the Bay of Naples.
According to mythology, Misenum was named after Misenus, a companion of Hector and trumpeter to Aeneas. Misenus is supposed to have drowned near here after a trumpet competition with the sea-god Triton, as recounted in Virgil's Aeneid.
In 38 BC, Misenum was the site where a short-lived pact was made between Octavian (heir of Julius Caesar, who later became the emperor Augustus), and his rival Sextus Pompeius.
In ancient times, Misenum was the largest base of the Roman navy, since its port (Portus Julius) was the base of the Classis Misenensis, the most important Roman fleet. It was first established as a naval base in 27 BC by Marcus Agrippa, the right-hand man of the emperor Augustus.
With its gorgeous natural setting close to the naval base and the nearby important Roman cities of Puteoli and Neapolis, Misenum became the site of Roman luxury villas.