The Carthusian monastery of San Martino is by far one of the largest religious monumental complexes in the city and one of the most successful examples of Baroque architecture and art together with the royal chapel of the Treasury of San Gennaro, and the fulcrum of Neapolitan painting of the seventeenth century. It has about one hundred halls, two churches, four chapels, three cloisters and hanging gardens.

After the Unification of Italy it has assumed the title of national monument and since 1866 it houses the National Museum of San Martino, born with the aim of telling the artistic and cultural history of the city. Inside the Carthusian complex is housed in some rooms the National Museum of San Martino, which has the intent of telling the story of Naples from the Bourbon era until the posthumous period.