Nemi: Diana's lake, Caligula's ships and the strawberries

Nemi is one of the smallest towns of the Castelli Romani, under two thousand people. It stands on a ridge at about 520 metres, above a round dark lake that the ancients called Diana’s mirror. In so small a place a goddess, an emperor and a fruit all meet.

The lake

Lake Nemi fills a crater of the Alban Hills volcano, the one we describe in the article on the Alban Hills volcano. It is small, about 1.7 square kilometres, and some thirty metres deep. The steep walls and the woods around it close it in like a bowl.

Diana’s sanctuary

On the north shore stood the sanctuary of Diana Nemorensis, Diana “of the wood”. After the fall of Alba Longa, in the middle of the seventh century BC, it became the religious centre of the Latin League, and it was greatly enlarged between the second century BC and the first century AD.

One of the strangest customs of the ancient world is tied to the sanctuary. The priest of Diana, the rex Nemorensis, the “king of the wood”, could be challenged to a duel by a runaway slave, who first had to pluck a bough from a sacred tree in the grove; whoever won took the office until the next challenge. The anthropologist James Frazer started from this story to write The Golden Bough, in 1890.

Caligula’s ships

On the bed of the lake lay two huge ships of the emperor Caligula, about 64 and 71 metres long.

In the 1920s and 1930s it was decided to bring them up: for the recovery, between 1929 and 1932, the level of the lake was lowered by about 22 metres. A Museum of the Roman Ships was built on the shore for them, between 1933 and 1939.

On the night of 31 May to 1 June 1944 a fire destroyed the museum and the ships; the most likely cause is the bombing of those days. The museum reopened in 1953, closed again in 1962 and reopened for good in 1988: today it shows scale models and finds. Since 11 March 2021 a lost mosaic of Caligula has also been back in Nemi.

The strawberries

Nemi is the town of strawberries, grown on the slopes of the crater. The strawberry festival is held every year on the first Sunday of June: the oldest trace in the town’s archive is a resolution of 1922 authorising the celebrations. Dates for each edition should be checked on the town’s channels.

The town

The centre is a handful of lanes around Palazzo Ruspoli, medieval, built by the Counts of Tusculum and remodelled in the Renaissance; today it is closed and in poor condition.

In short

• Where: Castelli Romani, on Lake Nemi, at about 520 metres.
• The sanctuary: Diana Nemorensis, religious centre of the Latins; the rex Nemorensis and The Golden Bough.
• The ships: two ships of Caligula, 64 and 71 metres, recovered in the 1920s and 1930s, burned in 1944.
• The strawberries: festival on the first Sunday of June, since 1922.
• Nearby: Castel Gandolfo and Lake Albano, the Castelli Romani in one day.