ancient Lacus Nemorensis
Crater lake in the Alban Hills, southeast of Rome, Italy.
Its area is about 0.67 sq mi (1.7 sq km), and it is 110 ft (34 m) deep. Nearby were a temple and grove sacred to the goddess Diana . Two ships dating from the reign of Caligula were raised from the lake bottom in the 1920s but were burned by the retreating German army in 1944, toward the end of World War II.