Lake Nemi (nā´mē), Latin Nemorensis lacus, small, picturesque crater lake, c.1 mi (1.6 km) long, in the Alban Hills, central Italy, SE of Rome. The sacred wood and the ruins of the celebrated temple of Diana are there. Two pleasure ships of the Roman emperor Caligula that were lying at the bottom of Lake Nemi for almost 2,000 years were raised (1930–31) from the lake after its level had been lowered c.70 ft (21 m). No valuables were found, but objects interesting from the artistic and technical point of view were recovered. During World War II the ships were destroyed (1944) by the retreating German forces.