The Castle is built on the islet of Megaride, where (according to legend) the mermaid Parthenope landed and gave name to the city. By the end of the 5^th century a group of monks settled in the place and founded the Cenobio of San Salvatore, whose church is still visible. In ducal times, the monks left the islet and a fortress was built in place of the old Cenobio.

In the 12^th century the Normans chose the site as their residence and gave the architect Buono the task of enlarging the fortress. The building of the tower called “Normandia” dates back to this period, other buildings were instead achieved by the Svevis.

The present denomination of the building dates back to the 14^th century. There are two different theories about its genesis: the first one concerns the particular design of the castle, which is egg-like; the other one (the most reliable one), instead, is relative to an old legend, according to which, the poet Virgilio hid a golden egg under the castle to grant stability to the islet and to the city itself.

The present design of the castle is the product of the renovation made in  the vice-royal age, after damages suffered in the siege of 1503.

Actually Castel dell’Ovo is one of the distinctive marks of the Neapolitan sight, with its powerful walls and its arcades, that make it a monument of exceptional beauty and of great historical interest.