The Baths of Caracalla were the second largest Roman public baths, or thermae, in Rome. It was built between AD 212 and 217, during the reigns of Septimius Severus and Caracalla. They would have had to install over 2,000t of material every day for six years in order to complete it in this time.
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. The bath was free and open to the public. The earthquake of 847 destroyed much of the building, along with many other Roman structures.
The building was heated by a hypocaust, a system of burning coal and wood underneath the ground to heat water provided by a dedicated aqueduct. It was in use up to the 19th century. The Aqua Antoniniana aqueduct, a branch of the earlier Aqua Marcia, by Caracalla was specifically built to serve the baths. It was most likely reconstructed by Garbrecht and Manderscheid to its current place.
In the 19th and early 20th century, the design of the baths was used as the inspiration for several modern structures, including St George's Hall in Liverpool and the original Pennsylvania Station in New York City. At the 1960 Summer Olympics, the venue hosted the gymnastics events.
References:The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.