Castel dell'Ovo, the oldest castle in Naples, Italy, is a prominent structure on the Gulf of Naples, located between the San Ferdinando and Chiaia neighborhoods, facing Via Partenope. Over time, it has undergone significant changes in its original appearance due to destructive events and reconstructions during the Angevin and Aragonese eras. Legend suggests that its name comes from a magic egg that, according to popular belief, the Latin poet Virgil had hidden in the dungeons of the castle, granting it the power to sustain the entire fortress. It is said that the breaking of this egg would cause the collapse of the castle and trigger catastrophes in Naples. During the 14th century, at the time of Joanna I, the castle suffered considerable damage, and the queen had to swear to have replaced the supposed magic egg to avoid panic among the population.

This legend, among many attributed to Virgil in the Middle Ages, arose possibly to explain in a fantastic way the popular name of the castle, "castello dell'ovo", which already existed in documents of the 13th century. The name is related to the ovular shape of the castle given by Roger the Norman in the previous century. The legend of the egg in the castle did not appear before the late Middle Ages and was invented, possibly to justify the popular name.

The Castel dell'Ovo is located on the tuff islet of Megaride, a place with a rich history dating back to the foundation of Parthenope in the eighth century BC. Initially owned by Lucius Licinius Lucullus, who built a splendid villa, the Villa of Licinius Lucullus, the area went through various stages, including occupation by Basilian monks. During the Norman domination, it became the seat of Roger the Norman, and later, during the reign of Alfonso V of Aragon, it underwent significant remodeling. At the time of the Spanish viceroys and the Bourbons, it was further fortified and lost its function as a royal residence.

After the Italian unification, the castle was in danger of demolition during the Risanamento project in 1871, but was finally restored in 1975. Today, the Castel dell'Ovo is part of the Santa Lucia district and hosts exhibitions, conferences and events in its spacious halls. Its base includes the tourist marina of Borgo Marinari, known for its restaurants and bars, being a visitable place in the city of Naples.