The Baths of Caracalla (Italian: Terme di Caracalla) were built between AD 212 and 216, during the reign of the Emperor Caracalla. Records show that the idea for the baths were drawn up by Septimius Severus, and merely completed or opened in the lifetime of Caracalla.
The bath complex covered approximately 25 hectares (33 ac). The bath building was 228 metres (750 ft) long, 116 metres (380 ft) wide and 38.5 metres (125 ft) estimated height, and could hold an estimated 1,600 bathers.
The baths consisted of a central 55.7 by 24 metre (183x79 ft) frigidarium (cold room) under three 32.9 meter (108 ft) high groin vaults, a double pool tepidarium (medium), and a 35 meter (115 ft) diameter caldarium (hot room), as well as two palaestras (gyms where wrestling and boxing was practised). The north end of the bath building contained a natatio or swimming pool. The natatio was roofless with bronze mirrors mounted overhead to direct sunlight into the pool area. The entire bath building was on a 6 metre (20 ft) high raised platform to allow for storage and furnaces under the building.
The libraries were located in exedrae on the east and west sides of the bath complex. The entire north wall of the complex was devoted to shops. The reservoirs on the south wall of the complex were fed with water from the Marcian Aqueduct.
The baths remained in use until the 6th century when the complex was taken by the Ostrogoths during the Gothic War, at which time the hydraulic installations were destroyed. 1