Baths of Caracalla: A Roman Public Bath Complex in Rome
Site at a Glance
- Rating
- 4.6
- Popularity
- Very High
- Country
- Italy
- Primary era
- Classical
- External website
- Open
- Eras represented
- Classical
- Civilizations
- Roman
- Site type
- Sanitation
- Remains
- Baths
On this page19 sections
History
The Baths of Caracalla are a Roman public bath complex in Rome, Italy, built under the Severan emperors between approximately AD 212 and 216 and inaugurated under Caracalla in AD 216. Caracalla was the commonly used name of Marcus Aurelius Antoninus, emperor from AD 211 to 217 and son of Septimius Severus. Known in antiquity as the Thermae Antoninianae, the baths formed part of an extensive Severan building programme in the southern part of the city and became one of Rome’s great centres of bathing, exercise, study, and social activity.
Severan construction and earlier occupation
The complex stood in Regio XII Piscina Publica, between the Via Nova and the Via Ardeatina. Its construction transformed land that had previously formed part of the horti Asiniani, a large garden estate developed by Gaius Asinius Pollio during the reign of Augustus. Caracalla appropriated the estate, and some earlier buildings were demolished to ground level, filled with earth, and incorporated into the foundations of the new baths. The project was linked with other Severan works in southern Rome, including the Via Nova and the Septizodium.
Among the earlier remains is a two-storey elite house built under Hadrian between AD 134 and 138. Part of it was demolished in AD 206 before the bath complex was constructed. Its decorated rooms included frescoed ceilings and a lararium, a household shrine, dedicated to Roman and Egyptian gods. Francesco Ficoroni excavated the house in the mid-eighteenth century, and G. B. Guidi investigated it again between 1860 and 1867.
Use, decoration, and repairs
The baths were free and open to the public. A thermae was more than a place for washing, combining cold, warm, and hot bathing with exercise, body care, reading, study, discussion, gardens, and other communal activities. The Baths of Caracalla remained fully operational during the fifth century and were described as one of Rome’s seven wonders. Estimates place their capacity at about 1,600 bathers at one time, with approximately 6,000 to 8,000 daily users.
Decoration continued under Elagabalus and Severus Alexander, while the outer enclosure and its porticoes were completed after Caracalla’s reign. The complex was repaired under Aurelian, probably after a fire, and later under Diocletian and Constantine the Great. Constantine modified the caldarium, the hot bathing room. Restoration work is also associated with Theodoric in the early sixth century.
A Christian pilgrimage centre called the titulus Fasciolae developed nearby in the mid-fourth century. The baths supplied water to the pilgrims and the associated church community. During the sixth and seventh centuries, parts of the complex were apparently used for the burial of pilgrims who died after receiving care at the nearby xenodochium, or charitable lodging and care centre, of Santi Nereo e Achilleo.
Water cut-off and abandonment
In AD 537, during the Gothic War, the Ostrogothic king Vitiges besieged Rome and cut the city’s water supply, including the aqueduct that served the baths. The complex consequently ceased to function and fell into disuse. Much of the surviving structure was destroyed by the earthquake of 847, after which the ruined buildings became a source of valuable construction material.
From at least the twelfth century, marble, stone, columns, and other elements were quarried from the ruins for churches and palaces. The area was used for vineyards and gardens in the fourteenth century. During the fifteenth century, Pope Pius II allowed material from the baths to be used for the Loggia of the Benediction at St Peter’s Basilica. In 1524, Pope Clement VII granted Cardinal Lorenzo Pucci permission to remove building materials for a new palace, and large-scale extraction continued during the sixteenth century.
Excavation and modern conservation
Renewed study began during the Renaissance, when Andrea Palladio, Giovanni Antonio Dosio, Antonio da Sangallo the Elder, Giovanni Battista Falda, Giambattista Nolli, and Giuliano da Sangallo drew the substantial remains. Excavations commissioned by Pope Paul III in 1545 and 1547 recovered sculptures, architectural fragments, lamps, intaglios, and cameos. The quantity of material led to the creation of the Museo Farnese, whose collections were later transferred to the Real Museo Borbonico.
Systematic modern excavation began with Count Egidio di Velo in 1824 and continued under Luigi Canina and Battista Guidi. Work between 1866 and 1869 revealed mosaics, porphyry columns, decorated capitals, and a torso of Hercules. Pietro Rosa excavated the eastern palaestra, an exercise court used especially for wrestling and boxing, in 1870, while Giuseppe Fiorelli uncovered further mosaics in 1878 and 1879. Excavation later extended into the outer precinct and underground galleries. The Mithraeum, a sanctuary of Mithra, was discovered by Ettore Ghislanzoni in 1912.
Restoration in the 1980s cleared dense vegetation and illegally built houses and repaired the southern wall, its cisterns, the southwestern library, and the octagonal hall identified as the Temple of Jupiter. An opera stage installed in the caldarium in the late 1930s was dismantled in 1998 and 1999. Later performances used a temporary movable stage outside the principal ancient structure, reducing pressure on the ruins. The baths have also hosted concerts and other cultural performances. Minor earthquake damage occurred in 2009, when the site was the only archaeological site in Rome affected by the earthquake near L’Aquila, and again in August 2016 during an earthquake in central Italy. The complex forms part of the UNESCO World Heritage Site covering Rome’s historic centre and is recognized for its cultural, artistic, historical, architectural, and religious importance.
Remains
The surviving remains preserve the large axial plan of a complex covering approximately 25 hectares. A nearly rectangular or square outer precinct enclosed the central bath building, gardens, porticoes, service areas, libraries, exedras, shops, fountains, and exercise facilities. The principal structure was raised on a platform about 6 metres high, while artificial platforms were created by removing or levelling parts of nearby hills. The central building measured approximately 214 by 110 metres and was set toward the northern side of the enclosure, leaving a particularly large garden court to the south.
Central bathing halls
Frigidarium
The central frigidarium, or cold hall, measured approximately 58 by 24 metres. Three groin vaults, each about 32.9 metres high, covered the space, and eight enormous Egyptian-granite columns supported the roof. Its marble floor contained four cold-water pools. Two were linked to the tepidarium, the warm bathing room, while two were connected by cascades to the open swimming pool, or natatio. Additional brick pools and a circular central pool surrounding a fountain formed part of the hall’s bathing arrangement.
Caldarium
The circular caldarium measured approximately 34 to 35 metres in diameter. Its dome was nearly 36 metres wide and rested on eight masonry piers. Large windows between the piers admitted light and solar heat while reducing the weight of the walls. Seven pools, each approximately 9.5 by 5 metres and about 1 metre deep, were associated with the room. Six survive, while Constantine’s restoration replaced the seventh with a small apse. The caldarium is now largely or completely demolished.
Natatio
The roofless natatio was an approximately Olympic-sized swimming pool measuring about 50 to 54 by 22 to 23 metres. Its walls rose more than 20 metres. Three huge grey-granite columns stood on its northern façade, which also contained several levels of statue niches. Bronze mirrors mounted above the pool directed sunlight into the bathing area. The natatio formed the open-water end of the principal bathing sequence, which ran through the cold, warm, and hot rooms.
Exercise courts and outer precinct
Palaestrae
Two palaestrae flanked the frigidarium. Their internal courts are described as approximately 50 by 20 metres, with broader internal-court dimensions also given as about 67 by 29 metres. These spaces accommodated wrestling, boxing, games, running, weightlifting, and other forms of exercise. The eastern palaestra is associated with the original location of the Farnese Bull, a sculptural group later recovered from the ruins.
Exedras and public facilities
The outer enclosure contained two symmetrical large exedras, semicircular recesses or halls used for seating, discussion, or display. It also included subsidiary gymnasia, fountains and nymphaea, lecture or work rooms, possible massage and body-care rooms, and shops or probable taverns and restaurants along the northeastern side. A stadium and a long semicircular exedra with seating occupied the area between the cisterns and the main bath building. The surviving ruins include sections of the stadium, porticoed courts, semicircular exedras, and service galleries.
Libraries, water supply, and service systems
Library and cisterns
The southern side contained large water cisterns, with Greek and Latin libraries and public reading rooms beside them. The surviving library measures approximately 38 by 22 metres. Three walls were lined with a total of 32 book niches. A larger central niche probably held a statue, while a masonry ledge may have served as a bench. The cisterns received water from the Aqua Antoniniana, a branch of the Aqua Marcia constructed or adapted specifically for the baths. The aqueduct entered on the southern side, and lead pipes connected the cisterns with the bathing rooms. Its exact route remains uncertain because only a few sections have been discovered.
Underground galleries and heating
Substructures beneath the raised platform held furnaces, fuel stores, service passages, and heating galleries. The heating system used a hypocaust, an underfloor arrangement in which hot air from furnaces circulated beneath raised floors and through hollow brick wall conduits. Furnaces and boilers, known as praefurnia, heated the water, while vaulted passages allowed the system to be maintained. Fuel stores may have held more than 2,000 tonnes of wood, and the furnaces are estimated to have consumed roughly 10 tonnes each day.
The subterranean galleries extend for hundreds of metres beneath the complex. They served as heating passages, sewers, and fuel-storage areas and included skylight-like openings for ventilation. An underground water mill, excavated from 1912 onward, is now considered ancient. Fire damage indicates that it burned in the third century and was later rebuilt with alterations. The complex also included changing rooms, private bathing rooms, latrines, saunas, a sudatorium, service courtyards, storage rooms for oils and sand, sunning rooms, and a shower known as a lavatio.
Mithraeum and ritual space
Mithraeum
The Mithraeum beneath the baths measures approximately 23 by 10 metres. It has a cross-vaulted ceiling, a black-and-white mosaic floor, benches along the walls, and a fresco of Mithra or a torchbearer. A roughly carved marble snake and a circular ritual pit covered by a marble slab were also found. The pit has been interpreted either as a fossa sanguinis, a feature associated with bull sacrifice and initiation, or as a trapdoor for staged entrances.
A rectangular opening in the Mithraeum floor led through a small tunnel beneath the main room to an adjoining chamber with a staircase. This arrangement is unusual for a Mithraeum, and its function remains uncertain. The sanctuary provides evidence of a religious use within the wider bathing complex, whose principal spaces were designed for public bathing, exercise, reading, and communal activity.
Construction, decoration, and surviving objects
The walls used Roman concrete, or opus caementicium, a concrete-like material made from lime mortar and aggregates such as volcanic pozzolana. Red brick faced the walls, while tuff and basalt were used in the structure and foundations. Marble, granite, porphyry, and other stones appeared in columns, floors, basins, wall coverings, and decoration. Construction used approximately 341,000 cubic metres of pozzolana and tuff, about 35,000 cubic metres of quicklime, and approximately 150,000 cubic metres of basalt for the foundations.
About 252 columns stood in the central block, including 16 more than 12 metres high. The largest granite columns in the frigidarium were about 12 metres long and weighed close to 100 tonnes. Vaults, groin vaults, domes, thick load-bearing walls, buttress-like masses, and reinforced zones between the frigidarium and natatio supported the immense spans. Roofs were generally tiled, while the caldarium had a dome; some vaulted coverings may have incorporated bronze or other metal structural elements.
Interior surfaces were richly finished with coloured marble, mosaics, frescoes, gilded bronze, sculptural groups, capitals, and large stone basins. More than 120 high-quality sculptures originally stood in the baths. The Farnese Bull was probably placed in the eastern palaestra, while the Farnese Hercules stood in the frigidarium. Both are now in the National Archaeological Museum in Naples, along with the Farnese Flora and a Roman group identified as Neoptolemus and Astyanax. Other recovered works include the Belvedere Torso, statues of Venus, a Bacchante, the group of Atreus and Thyestes, an Hermaphrodite, Minerva, and busts of the Severan emperors.
A colossal statue of Asclepius, approximately 4 metres high, was associated with the baths. An Aphrodite Anadyomene found in a nearby underground room in 1912 is now in the Museo Nazionale Romano at the Baths of Diocletian. The Athletes mosaics, which show competitors with their equipment and prizes, were discovered in 1824 in the eastern and western library exedras and are preserved in the Vatican Museums. Other mosaics depict dolphins, aquatic deities, animals, human figures, geometric designs, and mythological subjects.
Two large granite basins from the frigidarium were removed to Piazza Farnese, where they remain as fountains. A granite column from the natatio was transported to Florence in 1563 and now stands in Piazza Santa Trinita as the Column of Justice. The surviving ruins nevertheless retain the major axial arrangement, massive vaulted halls, libraries, cisterns, porticoed courts, service galleries, and sections of the outer precinct. Their design influenced later Roman buildings, including the Baths of Diocletian and the Basilica of Maxentius, and inspired modern structures such as St George’s Hall in Liverpool, the original Pennsylvania Station in New York, Chicago Union Station, the Senate of Canada Building, the Hollywood Theatre in Portland, and the former main hall of the University of Leipzig.
