Castel dell'Ovo (Egg Castle) is located on the former island of Megaride, now a peninsula, on the Gulf of Naples. The castle's name comes from a legend about the Roman poet Virgil, who had a reputation in the Middle Ages as a great sorcerer and predictor of the future. In the legend, Virgil put a magical egg into the foundations to support the fortifications. Had this egg been broken, the castle would have been destroyed and a series of disastrous events for Naples would have followed.
The Castel dell'Ovo is the oldest standing fortification in Naples. The island of Megaride was where Greek colonists from Cumae founded the original nucleus of the city in the 6th century BC. Its location affords it an excellent view of the Naples waterfront and the surrounding area. In the 1st century BC the Roman patrician Lucius Licinius Lucullus built the magnificent villa Castellum Lucullanum on the site. Fortified by Valentinian III in the mid-5th century, it was the site to which the last western Roman emperor, Romulus Augustulus, was exiled in 476. Eugippius founded a monastery on the site after 492.
The remains of the Roman-era structures and later fortifications were demolished by local residents in the 9th century to prevent their use by Saracen raiders. The first castle on the site was built by the Normans in the 12th century. Roger the Norman, conquering Naples in 1140, made Castel dell 'Ovo his seat. 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. It also served as a prison. The current appearance dates from the Aragonese domination (15th century).
It was struck by French and Spanish artillery during the Italian Wars; in the Neapolitan Republic of 1799 its guns were used by rebels to deter the philo-Bourbon population of the city. After a long period of decay the site got its current appearance during an extensive renovation project started in 1975.
In the 19th century a small fishing village called Borgo Marinaro, which is still extant, developed around the castle's eastern wall. It is now known for its marina and restaurants. The castle is rectangular in plan, approximately 200 by 45 metres at its widest, with a high bastion overlooking the causeway that connects it to the shore; the causeway is more than 100 metres long and a popular location for newlyweds to have their wedding photos taken. Inside the castle walls are several buildings that are often used for exhibitions and other special events. Behind the castle there is a long promontory once probably used as a docking area. A large round tower stands outside the castle walls to the southeast.
The Broch of Gurness is an Iron Age broch village. Settlement here began sometime between 500 and 200 BC. At the centre of the settlement is a stone tower or broch, which once probably reached a height of around 10 metres. Its interior is divided into sections by upright slabs. The tower features two skins of drystone walls, with stone-floored galleries in between. These are accessed by steps. Stone ledges suggest that there was once an upper storey with a timber floor. The roof would have been thatched, surrounded by a wall walk linked by stairs to the ground floor. The broch features two hearths and a subterranean stone cistern with steps leading down into it. It is thought to have some religious significance, relating to an Iron Age cult of the underground.
The remains of the central tower are up to 3.6 metres high, and the stone walls are up to 4.1 metres thick.