Baths of Caracalla
World Architecture
Baths of Caracalla
Rome, Italy
The Baths of Caracalla Thermae Antoninianae were built between a.d. 212 and 216 by the emperor
Marcus Aurelius Antoninus a.d. 188 217, usually known as Caracalla. Although in layout the Baths
of Caracalla largely emulated the model established about a century before in the Baths of Trajan,
their massive scale and opulent internal finishes were without precedent. Their fully integrated plan
and imposing scale and grandeur amply demonstrated the Romans design skills. Significantly, the
baths demonstrated the structural advances made possible through the masterful use of concrete to
span vast spaces using barrel and groin vaults, domes, and half-domes, as well as the sophisticated
mechanical engineering services developed by the Romans.
Public baths thermae were an essential part of all Roman towns. The majority of citizens lived in
crowded tenements insulae without running water or sanitary facilities, so communal baths were
constructed and made available to both sexes of all social classes. Entry was free. Generally, mixed
bathing was not favored, so the baths were open to women in the mornings and men in the afternoons
and evenings. The thermae were the center of Roman social lifepeople could meet friends there and
engage in any number of leisure and cultural pursuits on offer. As well as changing rooms, gymnasia,
saunas, and pools of various temperatures, there were libraries, museums, restaurants, bars, shops,
lecture theaters, concert halls, playing fields, gardens, and courtyards, all richly furnished with
mosaics, fountains, and statues. Although extremely costly to build, the baths were a political
investmenta means for the emperor to demonstrate his concern for the well-being of the
community.
The Baths of Caracalla occupied a 50-acre 20.25-hectare site. The complex was divided into three
parts: the rectangular main building, approximately 750 by 380 feet 225 by 115 meters and large enough to accommodate 1,600 bathers encircling landscaped parks and gardens and a perimeter ring
of shops, lecture halls, and pavilions. Laid out symmetrically, the compactly planned baths offered
identical bathing circuits on either side of the central and shorter axis. The sequence of bathing
spaces on that axis comprised the hot bath caldarium, warm bath tepidarium, and the cold bath
frigidarium in a large unheated central hall. The last, which also served as a foyer, was open on one
side, allowing easy access to the open-air swimming pool natatio. Changing rooms apodyteria,
gymnasia, or exercise yards palaestrae, with terraced porticoes, and sauna laconica were arranged
symmetrically on the transverse axis. Rooms for massage, manicure, and other services associated
with the bathing routine were featured on either side of the baths. Decorative interior finishes
colored marble veneers on walls, marble, basalt and granite columns and arches, and coarsely textured
black-and-white mosaic floorscreated a rich and sumptuous character.
Since the baths were public facilities that attracted large numbers of people, the gathering spaces
needed to be vast and uncluttered with structural elements. In the absence of structural impediments,
bathers were afforded extended views to various parts of the thermae. The Romans achieved these
objectives by exploiting the semicircular arch. The rectangular central hall of the Baths of Caracalla
demonstrated their structural method. It was roofed with an enormous semicircular intersecting
concrete vault divided into three compartments. Each was 108 feet 30 meters high and rested at the corners on enormous piers. Clerestory windows adequately lit the hall.
Water for the Baths of Caracalla flowed from a branch of the Aqua Marcia aqueduct into a huge
reservoir, divided into eighteen chambers with a total capacity of about 2.2 million gallons 10 million
liters. The water was carried through pipes laid underneath the gardens to the main building, where it
was distributed directly to the cold pools, or to wood-fired boilers, where it was heated for the warm
and hot baths. For ease of inspection and maintenance, distribution pipes and waste drains were
located in separate tunnels. A separate network of tunnels was used to store wood for about fifty
furnaces praefurnia that heated the saunas laconica and other rooms via a hot-air system
hypocausta beneath the floors. The heated rooms were on the southwestern side of the complex to
gain maximum benefit from the sun all had large windows. The hottest room, the circular, protruding
caldarium, was covered by a 115-foot-diameter 35-meter dome, higher than the Pantheons and only
slightly less in span.
The Baths of Caracalla are now in ruins, but their soaring height and impressive scale allow visitors to
appreciate their size and massiveness.