Location
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. It has a surface of 1.67 km2 (0.64 sq mi) and a maximum depth of 33 meters (108 ft).
There is considerable speculation regarding why the emperor Caligula chose to build two large ships on such a small lake. From the size of the ships it was long held that they were pleasure barges, though, as the lake was sacred, no ship could sail on it under Roman law (Pliny the Younger, Litterae VIII-20) implying a religious exemption.
Caligula particularly favoured the Egyptian Isis cult which he had established in Rome and also supported that of Diana Nemorensis whom, in the Roman tradition of syncretism, he likely viewed as an aspect of Isis.
Situated on opposite sides of the lake and atop the crater walls, are the towns of Genzano which was dedicated by the Romans to the goddess Cynthia, a cult associated with that of Diana Nemorensis and Nemi, which did not exist in Roman times. The name Nemi derives from the Latin nemus Aricinum (grove of Ariccia), Ariccia being an important nearby town associated with the worship of Diana and the god Virbius. Located at Nemi are the ruins of an ancient temple dedicated to Diana, which was connected by the Via Virbia to the Via Appia (the Roman road between Rome and Brindisi).
During the Roman empire the area around Genzano was used by wealthy Roman citizens for its clean air, uncontaminated water and cooler temperatures during the hot summer months. The lake has its own microclimate and is protected from wind by the crater walls. Goethe, Lord Byron and Gounod all lived in Nemi and saw the magical reflection of the Moon seen in the center of the lake during summer. This phenomenon is the source of the Roman name for the lake, Speculum Dianae (Diana's Mirror).
Read more about this topic: Nemi Ships