The Baths of Diocletian were the most magnificent spa facility ever built in Rome. Erected between 298 and 306 AD, had an area of over 13 hectares and could accommodate up to 3000 people simultaneously, in a path that wound through gyms, libraries, a pool of more than 3500 square meters and the environments that formed the heart of every thermal plant: frigidarium, tepidarium and caldarium. These very large halls were transformed by Michelangelo for the construction of the Basilica of St. Mary of the Angels and Martyrs Christians: in other rooms of the Baths was built, designed by the artist himself, the Convent of the Carthusians.

Original seat of the Roman National Museum since its establishment in 1889, the baths and the Certosa are the subject of a restoration process that has so far allowed the reopening of part of the monumental complex of two sections and a detailed exposition of the museum, the Chamber of Early History of Peoples Latinos and the Epigraphic on Written Communication in the Roman world.

The visitor can then, in addition to the museum to visit, also enjoy the sumptuous and imposing Tenth Chamber, in which are exhibited the great tomb of Platorini and two chamber tombs from the necropolis of the Via Portuensis with frescoes and stucco; it is possible to walk on the large Michelangiolesco Cloister of the Certosa, now an unexpected oasis of peace and tranquility just steps dall'affollatissima Termini station, where an exhibition of more than 400 works, including statues, reliefs, altars, sarcophagi from the Roman territory.