Under the Bourbon Monarchy, another collection was added to the museum: the one hosted in the Secret Cabinet. This collection has a unique story: the pieces showcases came from Pompeii and Herculaneum and for years they were hidden because of their erotic and sexual nature. At the beginning only adult people could visit the rooms, later to avoid to be considered lascivious the collection was locked up.
Only when Garibaldi conquered the city the door of this secret rooms were opened again. However it took more than a century to completely open it to the public. Visitors under the age of 14 can only entered the rooms with an adult.