The National Roman Museum-Thermae of Diocletian was founded in 1889 to collect the antiquities of Rome and was recently reopened to the public. 

Housed within the imposing Diocletian complex, it contains a considerable and valuable collection of epigraphic material, consisting of inscriptions and terracottas and a section on the Protohistory of the Latin Peoples consisting of materials and trousseaus coming from the Osteria dell'Orsa, Castiglione, and Fidene. It includes many statues, sarcophagi, and funerary trousseaus.

The Garden of the Five Hundred, characterized by an enormous marble fountain, and the Large Cloister, called of Michelangelo, where a section of lesser statues and various archaeological materials is exhibited, are part of the complex of the Museum.

The epigraphical section was formed in the first half of the nineteenth century and today is completely restored.