In the 1800s a small fishing village (Borgo Marinari) developed around the castle's eastern wall. This village remains, now known for its marina and restaurants. The The castle is connected by a causeway.

Castel dell'Ovo (in Italian, Egg Castle) is a castle located on the former island of Megaride, now a peninsula, on the gulf of Naples. The castle's name comes from a medieval legend which tells that the Roman poet Virgil, who developed a medieval reputation as a great sorcerer as well, put a magical egg in the foundations to support them. The remains of the Roman-era structures and later fortifications were demolished by local residents in the ninth century to prevent their use by Saracen raiders. The first castle on the site was built by the Normans in the 12th century. The importance of the Castel dell'Ovo began to decline when king Charles I of Anjou built a new castle, Castel Nuovo, and moved his court there. Castel dell'Ovo became the seat of the Royal Chamber and of the State Treasury.