Discover Baths of Diocletian (Museo Nazionale Romano)

The Museo Nazionale Romano was instituted in 1889 to house the antiquities of Rome, and Turismo Roma records that it holds the most important archaeological collection in the world. The collection is divided across several sites — Terme di Diocleziano, Palazzo Massimo alle Terme, Palazzo Altemps and Crypta Balbi — with the material grouped by where it came from, what it is and which collection it belongs to.

Since 1889, part of the most imposing bath complex in Rome has been the seat of the Roman antiquities section. In antiquity the complex occupied a vast area between what are now via Torino, via Volturno, piazza dei Cinquecento and via XX Settembre.

The baths were the largest in Rome. Willed by the emperor Maximian and dedicated to Diocletian, with whom Maximian shared command of the empire, they covered a full 13 hectares and could hold up to 3,000 people. The inauguration took place between 305 and 306 AD.

They followed the usual plan of the great Roman baths, with the main rooms — calidarium, tepidarium and frigidarium — arranged along a central axis, recognisable today in the Basilica of Santa Maria degli Angeli.

They stopped working because the water stopped. The baths remained in operation until the middle of the 6th century, when the Gothic War caused serious damage throughout the city, and in particular the interruption of the water supply.

What the museum displays here is largely writing in stone. The garden towards piazza dei Cinquecento, the entrance to the Museum since its origins, holds epigraphic material, mostly funerary, along with varied architectural material; the epigraphic section illustrates the birth and spread of Latin writing.

The plan is the standard one, carried out at the largest scale Rome attempted. Turismo Roma records that the baths took up the usual scheme of the great Roman baths, characterised by the arrangement of the main rooms — calidarium, tepidarium and frigidarium — along a central axis. That axis is recognisable today in the Basilica of Santa Maria degli Angeli.

The corners and flanks carried the specialised rooms. An octagonal hall stands at the western corner, at the junction with today's via Parigi, and now houses the Museo dell'Arte Salvata.

Two circular halls flanked the great exedra. One of them, on the west side, has been transformed into the church of San Bernardo alle Terme.

Between those halls and the exedra were two rectangular rooms, probably libraries, and the exedra itself may have had the function of a theatre.

On the opposite side, two further exedrae survive, belonging to the eastern corner of the enclosure, where conferences and public readings took place.

The museum layer is architecture too. The institution of the Museum in 1889 redefined the arrangement of the works that occupy the four ambulatories, and the garden towards piazza dei Cinquecento has been the entrance to the Museum since its origins.

It was an imperial commission with a political dedication. The baths were willed by the emperor Maximian and the completed complex was dedicated to Diocletian, with whom Maximian shared command of the empire. The inauguration took place between 305 and 306 AD.

The size was the engineering problem. At 13 hectares, with capacity for 3,000 people, this was the most imposing bath complex in Rome, occupying in antiquity the area between today's via Torino, via Volturno, piazza dei Cinquecento and via XX Settembre.

Water was the system it depended on, and the reason it ended. The complex remained in operation until the middle of the 6th century, when the Gothic War caused serious damage throughout the city, in particular the interruption of the water supply. A bath building without aqueducts is masonry.

Its second construction was adaptive. The halls were not demolished but re-roofed and re-used: the main axis became the Basilica of Santa Maria degli Angeli, a circular hall became the church of San Bernardo alle Terme, and much later the octagonal hall became the Museo dell'Arte Salvata.

Its third was museological. From 1889 part of the complex was fitted out as the Roman antiquities section of the new Museo Nazionale Romano, an intervention that redefined the arrangement of the works occupying the four ambulatories.

When is it open? Turismo Roma publishes only that it is closed on Mondays with last entry at 18.00. No opening time is given; the city tells visitors to check the official site.

How much does it cost? No price is published. The page gives a ticketing link on portale.museiitaliani.it and no amount, so none is quoted here.

What is the Museo Nazionale Romano? An institution created in 1889 to house the antiquities of Rome, which Turismo Roma says holds the most important archaeological collection in the world. It is spread across four sites: Terme di Diocleziano, Palazzo Massimo alle Terme, Palazzo Altemps and Crypta Balbi.

How big were the baths? 13 hectares — the largest in Rome — with room for 3,000 people.

When were they built? They were inaugurated between 305 and 306 AD, willed by the emperor Maximian and dedicated to Diocletian.

Why did they stop working? They ran until the middle of the 6th century, when the Gothic War damaged the city and interrupted the water supply.

Where are the actual bathing rooms? The axis of calidarium, tepidarium and frigidarium is recognisable today in the Basilica of Santa Maria degli Angeli.

What else of the complex still stands? An octagonal hall at the western corner on via Parigi, now the Museo dell'Arte Salvata; a circular hall turned into the church of San Bernardo alle Terme; two rectangular rooms, probably libraries; the great exedra, perhaps a theatre; and two exedrae of the eastern corner, where conferences and public readings took place.

What is actually on display? Above all epigraphy: funerary stelae mostly of the late republic and early empire, altars of the first two centuries of the empire, sarcophagi and funerary statues, and a section illustrating the birth and spread of Latin writing.

How is it arranged? On the conventional topographic criterion: inside the Servian walls, the consular roads, the Tiber, and so on.

Where is it? Viale Enrico De Nicola 79, by Termini station, piazza della Repubblica and via Nazionale.