NEMORENSIS LACUS (mod. Nemi), a lake in the Alban hills, in an extinct subsidiary crater in the outer ring of the ancient Alban crater, east of the Lake of Albano. It is about 31 m. in diameter and some I i o ft. deep; the precipitous slopes of its basin are over 30o ft. high, and are mainly cultivated. In ancient times it was included in the territory of Aricia and bore the name "Mirror of Diana." The worship of Diana here was originally cele brated with human sacrifices; even in imperial times the priest of Diana was a man of low condition, a gladiator or fugitive slave, who won his position by slaying his predecessor in fight, having first plucked a mistletoe bough from the sacred grove. The temple itself was one of the richest in Latium; Octavian borrowed money from it in 31 B.C. The remains of its precinct are situated a little above the level of the lake, on the north-east—a large platform, the back of which is formed by a wall of concrete, with niches, resting against the cliffs. Excavations (now covered in again) led to the discovery of the temple itself, a comparatively small build ing, 98 by 52 ft., containing objects, none earlier than the 4th
century B.C. A road descended to it from the Via Appia from the south-west. The lake is drained by a tunnel of about 2 m. long, of Roman date.
On the west side of the lake remains of two ships (really floating palaces moored to the shore) have been found, one belonging to the time of Caligula (as is indicated by an inscription on a lead pipe), and measuring 210 ft. long by 66 wide, the other even larger, 233 by 8o feet. The first was decorated with marbles and mosaics, and with some very fine bronze beamheads, with heads of wolves and lions having rings for hawsers in their mouths (and one of a Medusa), now in the Museo delle Terme at Rome. Var ious attempts have been made to raise th6 first ship, from the middle of the 15th century onwards, and the ancient emissarium has now been cleared in order to lay bare the remains of the ships. Caesar had a villa constructed there.
See J. G. Frazer, The Golden Bough (1913-14) ; L. Morpurgo in Monumenti dei Lincei, xiii. (1903), 297 sqq.