The Nemi ships were two ships, of different sizes, built under the reign of the Roman emperor Caligula in the 1st century AD on Lake Nemi. Although the purpose of the ships is speculated upon, the larger ship was an elaborate floating palace, which contained quantities of marble, mosaic floors, heating and plumbing, and amenities such as baths. Both ships featured technology thought to have been developed historically later. It has been stated that the emperor was influenced by the lavish lifestyles of the Hellenistic rulers of Syracuse and Ptolemaic Egypt. Recovered from the lake bed in 1929, the ships were destroyed by fire in 1944 during World War II.
The larger ship was 73 m (240 ft) in length, with a beam of 24 m (79 ft). The other ship was 70 m (230 ft) long, with a beam (width) of 20 m (66 ft).