Gaiola Island is a small island located off the coast of Naples, Italy, in the Gulf of Naples. It is part of the Gaiola Underwater Park, a protected marine reserve that includes the island and the surrounding sea area. The island is uninhabited and is only accessible by boat.

The island has a rich history and has been inhabited since the Roman times. In the 19th century, a villa was built on the island by the Scottish engineer Thomas Gordon, who bought the island and turned it into a private residence. The villa was later purchased by the German industrialist Otto Grunback, who renovated it and used it as a vacation home.

The island is surrounded by crystal-clear waters and is a popular destination for scuba diving and snorkeling due to its rich marine life. The underwater park is home to various species of fish, seahorses, octopuses, and other sea creatures.

Gaiola Island is also known for its eerie reputation as a "cursed" island due to a series of mysterious deaths and misfortunes that have befallen some of its past owners. Despite this, the island remains a popular tourist attraction and a unique natural landmark in the Gulf of Naples.