Lake Nemi

Lake Nemi (Italian: Lago di Nemi, Latin: Nemorensis Lacus) is a small circular volcanic lake in the Lazio region of Italy 30 km (19 mi) south of Rome, taking its name from Nemi, the largest town in the area, that overlooks it from a height.

The lake is most famous for its sunken Roman ships. These ships were very large and technologically advanced for their time.
At the Hotel Diana on the Western edge of the crater at Via Nemorense, there is a fine exhibit of the archeological excavation of the late 1920s which exposed the enormous structure which Caligula had ordered built. For more information about this tantalizing exercise in Roman digs see nemi ships.

Emperors Caligula and Tiberius sailed Lake Nemi not merely to cool off in summer, but to assert themselves as Nemorensis, rulers aligning with the Stars, wedded to Earth's perpetual life-force.