Baths of Diocletian, Rome

The Baths of Diocletian (Italian: Terme di Diocleziano) in Rome are a monumental ancient Roman complex, restored and modified by Michelangelo in the 16th century, and a museum.

Part of the Roman National Museum, the architectural complex, located close to the Termini rail station and the Palazzo Massimo Museum, is one of the most popular archaeological museums and sites in Rome, with about 1 million yearly visitors.

Above: a view of the Aula VIII of the Baths of Diocletian; photo: Carole Raddato (CC BY-SA 2.0),

History and architecture of the Roman thermal complex

Built in the early 4th century AD by Emperor Diocletian, the Baths, spanning an area of 13 hectares, were the largest thermal complex in the Roman Empire; It is estimated that they could accommodate up to 3,000 people.
The Baths included – along with typical thermal halls, such as a frigidarium, a caldarium, and a tepidarium – a large semicircular theater (which stood where Piazza dell’ Esedra now is), gymnasiums, a library, gardens, and a 3,500-square-meter (37,600-square-foot) swimming pool.
The complex was an imposing ensemble of vaulted brick structures, clad in polychrome marbles and stucco and decorated with frescoes and mosaics, now largely lost.

The plan of the Baths of Diocletian somewhat reproduces that of the Baths of Caracalla, with a central block located inside a larger, almost square, precinct 376 x 361 meters (1,233 x  1,184 feet) wide.
As usual, during the Roman Empire, the thermal complex was more than a place in which people took baths (most houses didn’t have a private bath at the time), it was indeed a popular venue where Romans met, socialized, did business, lazed, relaxed, and discussed politics and sports. That’s why many Roman Emperors – Agrippa, Nero, Titus, Trajan, Caracalla, Diocletian, and Constantine – commissioned the construction of thermal complexes in Rome, intending to gain popularity and immortalize their name.

View of the Baths of Diocletian complex in Rome today; photo by Mr No (CC BY 3.0).

A model of the original layout of the Baths of Diocletian on view at the Museo della Civiltà Romana; photo Magnus Manske (CC BY 2.0).

The footprint of the Baths of Diocletian superimposed on a modern satellite view of Rome, the Termini rail station is in the lower-right part of the image; image Inexhibit.

Photo: faungg’s (CC BY-ND 2.0).

Michelangelo’s buildings

Like most antique buildings in Rome, after the fall of the Roman Empire, the Baths were abandoned and fell into ruins until 1561, when Michelangelo was commissioned by Pope Pius IV to design the renovation of part of the complex, in order to accommodate a Carthusian monastery and the Church of Saint Mary of the Angels and the Martyrs.
The buildings designed by Michelangelo (together with Jacopo del Duca) still visible today include a 10,000-square-meter (107,600-square-feet) cloister (known as Chiostro Grande or Michelangelo’s Cloister), a smaller cloister known as Chiostro Ludovisi, and the church (though the latter was substantially modified in the 18th century after a project by Luigi Vanvitelli).

Therefore, the visit to the National Roman Museum at the Baths of Diocletian offers the unique possibility to see, along with the ruins of the thermal complex, an impressive ensemble of antique artifacts on view in the exhibition spaces,

In 1898, the State of Italy established the home of the National Roman Museum in the Baths of Diocletian, thus transforming part of it into a public museum. From 2008 to 2014, the Baths underwent major restoration and renovation works, which opened to the public for the first time parts of the complex, such as the small cloister and the ancient swimming pool, were previously inaccessible.

Church of Saint Mary of the Angels and the Martyrs, interior view; photo: Telwink (CC BY-NC-ND 2.0).

Views of Michelangelo’s Cloister; photos by -JvL- (CC BY 2.0).

Model of the Baths of Diocletian and the Charterhouse; photo: Carole Raddato (CC BY-SA 2.0).

Museums and archaeological collections

Along with being a grandiose archaeological and architectural site, the Baths of Diocletian accommodate two museums – the Epigraphical Museum and the Protohistorical Museum – and an impressive permanent exhibition of ancient sculptural works, located in the Michelangelo’s cloister and other halls of the complex. The ticket gives access to the thermal complex remains, the cloisters, and all the museums part of the National Roman Museum network, including those located in the Baths.

The Epigraphical Museum holds a 10,000-piece collection of ancient inscriptions from the National Roman Museum, about 1,000 pieces of which are on permanent display on the three floors of the museum, and illustrates the origins and development of the Latin language.

The Protohistorical Museum is dedicated to the history of the populations that inhabited the Lazio region (the Italian region in which Rome is located) from the 12th century BC to the birth of Rome and displays various antique artifacts, including small sculptures, votive statuettes, vases, bronze objects, arms, ornaments, and jewels.

Finally, as anticipated, about 400 sculptural objects – including statues, sarcophagi, altarpieces, and architectural decorative elements – are permanently on view under the open arcades of Michelangelo’s Cloister and in other exhibition spaces in the complex.

The Baths of Diocletian also host major temporary exhibitions (including, in the last years, those dedicated to Auguste Rodin, Henry Moore, and Jean Arp), recitals, concerts, educational programs, and special events. The complex and the museums are fully accessible to physically impaired people.

Sculptures on view in Michelangelo’s Cloister; photo: Giulio Gigante (CC BY-SA 2.0).

Marble strigilated sarcophagus, 3rd century AD; photo: Richard Mortel (CC BY-NC-SA 2.0)

Sarcophagus with Dionysus and Ariadne, 3rd century AD; photo: Egisto Sani (CC BY-NC-SA 2.0).

Interior view of the Epigraphical Museum; photo: Klaus Wagensonner (CC BY-NC-ND 2.0).