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Roman Baths, Bath
Stall Street, Bath, UK
associated engineer
Not known
date  circa 76 AD onwards
UK era  Roman  |  category  Building  |  reference  ST749647
The Roman spa complex at Bath is constructed around Britain's only active hot spring, from which the water emerges at temperatures up to about 49 degrees Celsius. Its structures are perhaps the most well-known we have in Britain from the Roman period. The Grade I listed spa is a Scheduled Monument and part of the city’s World Heritage Site. It has been restored and is a popular visitor attraction.
The spa complex dates to the end of the first century, though the site is likely to have been important from Iron Age times around 700 BC. Its focus was the sacred spring, where the Celtic Dobunni people worshipped the native goddess Sulis, who was believed to have healing powers. Legend says the spring was discovered in the 9th century BC, by Prince (later King) Bladud, whose leprosy was cured by the waters.
The source of the spring is a deep artesian reservoir formed during the Jurassic period, fed by rainfall percolating down from the Mendip Hills. The mineral-rich hot water rises through the limestone bedrock from the Pennyquick geological fault to the surface, delivering some 1.17 million litres per day at temperatures ranging between 40 and 48.9 degrees Celsius.
The Romans reached Britain in 43 AD and spread westwards, eventually crossing the River Avon and reaching the thermal spring. They too adopted the site as sacred, identifying Sulis with their own goddess Minerva. By 76 AD, they had built a religious spa here, including a temple dedicated to Sulis Minerva. A town, known as Aquae Sulis (waters of Sulis), developed around the spa and now forms the heart of the city of Bath. (The first record of the spa is 76 AD but it is thought the baths and temple are earlier, exact date unknown.)
The Romans constructed an open reservoir, or cistern, within a rectangular enclosure, about 13.7m by 19.8m, located below the present King’s Bath. The cistern consists of an impermeable wall, founded on oak piles, around the spot where the spring rises to the surface. In plan it forms an irregular octagon, with a maximum diameter of about 15.2m. The walls are 1.8m to 2.1m high, 910mm thick and lined with lead more than 13mm thick. Their massive stone blocks are held in place with iron clamps and topped by a stone parapet. Presumably, a form of cofferdam must have been constructed to enable the works.
The reservoir occupied the south east corner of the temple courtyard, with the temple at the north west of the spring. It was Classical Roman in style and stood on a podium more than 2m high. The only other Classical temple known in Britain is the temple of Claudius at Colchester.
Steps up to the temple entrance were flanked by four large Corinthian columns supporting a frieze and a pediment decorated with a male gorgon’s head. A statue of the goddess stood inside, lit only by the temple fire and daylight from the doorway. A great altar in front of the temple was a focus for worship, rituals and sacrifices.
South east of the spring is the Great Bath, a hot swimming pool that is the central feature of the complex. It occupies a spacious hall (now roofless) 33.5m long and 20.7m wide. The bath is 1.5m deep and lined with lead sheets. It measures 25.3m by 12.2m at the top and 22.3m by 8.8m at the bottom, with four steep steps along all sides. It is surrounded by a broad freestone platform with three recesses some 5.5m wide on the north and south sides, presumably rest areas for bathers. The walls were of coursed masonry 710mm thick. The roof was originally of pitched timber supported on slender columns, six on each long side of the bath, and pilasters in the walls.
On the east side of the Great Bath are a large rectangular tepid pool, two apsidal baths to the north and south of the pool, and two hypocausts. The pool is 9.1m long, 4.6m wide and 1.5m deep, with steps at the south end. It was surrounded by a flagged platform, and plastered walls with square pilasters. The original roof was probably of pitched timber.
The hypocausts — rooms with underfloor heating — were superheated by furnaces. The floor of each room were supported on a grid of short columns of tiles (pilae), between which hot air circulated to raise the temperature of the walls and floor above. Their purposes were similar to modern saunas (laconica, dry sweating rooms) and steam rooms (sudatoria, wet sweating rooms).
On the west side of the Great Bath is the Circular Bath, an oval bath plus four rectangular baths, several hypocausts and the latrines. The Circular Bath stands in a chamber measuring 10.1m by 11.9m, once pilastered and roofed. The bath is 8.8m in diameter and 1.5m deep, and originally lined with lead. Outfall drains run south towards the latrines. The Circular Bath was used as a cold plunge pool (frigidarium, cool room with a cold water bath). An underwater plinth at one side of the bath is probably the base for a fountain.
The baths were fed with water from the cistern via outlets in its walls, which could be closed with timber plugs a foot square. One outlet on the south side of the cistern supplied a pipe running south east to the Great Bath. Another may have supplied the Circular Bath to the south, though archaeological evidence is yet to be uncovered.
One outlet on the east side opened into a large stone culvert, which passed under an arch in the enclosure wall and eastwards, carrying the overflows from the cistern, Great Bath and east baths before turning south east towards an outfall to the river. The start of the culvert was used a dipping place to draw water for drinking and to offer gifts to the gods. Offerings were also thrown into the open cistern.
Other than heated rooms and cold pools, the facilities included changing rooms (apodyteria), swimming pools, hot rooms with hot baths (calidaria) and warm rooms with tepid pools (tepidaria), along with rooms for exercise (palaestrae), massage and other treatments.
The Romans did not wash with soap, though soap was used medicinally for treating diseases. Spa-goers exercised and spent time in the hypocaust rooms, applied scented oils and then cleaned their skins with a J-shaped metal scraper (strigil) before progressing through the baths from hot to warm to cold. Mixed bathing was not usual, though it is not clear whether segregated male and female bathers used separate areas or visited the baths at different times.
When completed the thermal baths (thermae) probably covered about 0.6 hectares. The spa complex was extended over time, covering its greatest area by the 4th century — perhaps as much as 3 hectares.
During the 2nd century, the spring and reservoir were enclosed within a barrel vaulted building. Six stone blocks remaining within the cistern may be the bases of supports for a portico. The timber roof of the Great Bath was replaced with a barrel vault of hollow ceramic box tiles, 20m above the water, and the slender columns were made larger, with bases projecting into the bath, to carry the additional load. The roof of the tepid bath might have been replaced with tiles at the same time. A colonnaded ambulatory was constructed around the perimeter of the temple courtyard, along with a building depicting the four seasons in the north of the courtyard and small side chapels to the temple.
The temple at Aquae Sulis was used for worship until the late 4th century. After emperor Theodosius I ordered the closure of pagan temples throughout the Roman empire (391 AD), it was neglected and eventually collapsed. Some of the pediment carvings survived, as they were reused as paving stones in the courtyard.
The Romans withdrew from Britain in the early 5th century, probably from around 410 AD onwards. The baths of Aquae Sulis fell into disuse and disrepair before being destroyed by flooding from the Avon. In the 6th or 7th century, the barrel vault over the spring collapsed.
In 757 AD, land was granted to the brothers of the monastery of St Peter in Bath, and a new monastery built to the north east of the sacred spring. Later, a Norman cathedral, constructed between 1088 and 1244, replaced the Saxon abbey. By the 12th century, the spring was enclosed within the monastery grounds and the King’s Bath founded on the shell of the Roman cistern. A statue of King Bladud overlooks the bath (though dated 1699, it is much earlier).
In 1576, the Corporation of Bath built the Queen's Bath to the south of the spring. Two years later, a drinking fountain was installed at the baths. In the 17th century, a seat known as the Master of the Baths chair was installed on the south side of the King’s Bath.
During the 17th century, doctors prescribed drinking the spa’s thermal waters to treat internal afflictions. In 1706, the first Pump Room opened above the spring, giving patients direct access to its water. It was then a simple single storey stone building with a pump and provision for musical entertainment, extended in 1751.
The complex of Roman baths was rediscovered in the 18th century. In 1727, the gilt bronze head of Sulis Minerva was found during sewer excavation and tiles from the south west part of the baths were unearthed in Stall Street. In 1755, the medieval priory house adjoining the south east corner of the abbey were being demolished for construction of baths for the 2nd Duke of Kingston. Under the building was a 10th century cemetery, but beneath that, Roman masonry. Within a couple of years, the eastern range of baths, hypocausts and part of the Great Bath had been uncovered.
The old Pump Room was replaced with the present Grand Pump Room in Bath stone. It is situated above the site of the Roman temple precinct. The building, with north and south colonnades on Stall Street, was built between 1784 and 1799. It was begun by Thomas Baldwin (c.1750-1820) and completed by John Palmer (c.1738-1817).
In 1790, the temple pediment was found. Around 1800, and in 1825 and 1868-9, structures associated with the Great Bath and the hypocausts south west of it were discovered in the vicinity of York Street and Stall Street. The full extent of the thermae remained unknown.
In 1869, Major Charles Edward Davis (1827-1902), the city architect, discovered Roman thermal work at the site of the King's Bath. In 1877-8, he exposed the Roman cistern beneath the bath and part of the culvert.
In 1878, the Corporation of Bath, who already owned the King's and Queen's Baths, purchased the Kingston Baths and commenced drainage works, uncovering more Roman remains 4.6m to 6.1m below the ground level. Davis continued his investigations, discovering the Great Bath and excavating its north side and ends in 1880-1. In 1883-6, the 16th century Queen's Bath was mostly demolished revealing the Circular Bath and associated hypocausts.
Davis designed a replacement for the Queen's Bath — the Douche and Massage Baths — constructed 1886-9. The building incorporated the surviving parts of the original bath and the private baths constructed in 1796, along with an arch over York Street.
In 1893-5, he discovered Roman masonry under the eastern extension of the Pump Room in 1893-5, the dipping place in 1894, more of the culvert including its timber duct in 1895 and a rectangular bath at the edge of the west range of baths, under Stall Street, in 1896.
The colonnades and balcony around the Great Bath and the museum buildings were constructed in 1889-97, to a scaled-down version of an 1894 design by architect John McKean Brydon (1840-1901), omitting Brydon’s roof over the Great Bath. The Great Bath’s parapet life-size statues of Roman emperors (Julius Caesar, Claudius, Vespasian, Hadrian and Constantine the Great), governors of Britannia (Publius Ostorius Scapula, Gaius Suetonius Paulinus and Gnaeus Julius Agricola) and the head of Roma are sculpted by George Anderson Lawson (1832-1904).
In 1897, the site was opened to the public. Uncovering and conserving more of the Roman baths complex continued throughout the 20th century. In the 1920s, further work was undertaken to the east baths, plus demolition of the Kingston Baths (1923) and glazing to the loggia above the north side of the Great Bath (circa 1925).
In June 1950, the Roman baths and museum were Grade I listed. In August 1972, the Queen’s Bath was Grade II listed. (Both listings amended October 2010). The baths are a Scheduled Monument (Bath and North East Somerset County Monument No.82) and probably the finest non-military Roman structures in Britain.
Between 1965 and 1983, excavations were carried out beneath the Grand Pump Room and at the spring. In 1972, most of the Douche and Massage Baths building was demolished.
The baths were used for curative bathing and swimming until the 1970s. They closed in October 1978, when contamination with the amoeba Naegleria fowleri resulted in the death of a young swimmer. The water in the baths is green, owing to algal growth promoted by sunlight.
In 1981-3, the temple precinct was excavated. In 1989-90, the vandalised statue of Caesar was replaced with a copy of the original by Laurence Tyndall.
In December 1987, the City of Bath was inscribed as a UNESCO World Heritage Site (number 428), chiefly for its Roman and Georgian associations. More recently, in 2011, a five-year £5.5m redevelopment project was completed to preserve the site of the Roman baths and improve accessibility. Stonework was laser cleaned and detritus removed. Audio guides, projections and actors are used to bring the history of the spa to life.
Visitors enter at first floor level and look down into the Great Bath. Beyond the western end of the Great Bath lies the Circular Bath and to its north the cistern capturing sacred spring. The cistern is not accessible to the public, though its hot waters are piped to the bath above. The Roman structure is now roofed in concrete, forming the floor to the modern King's Bath. Elsewhere the workings of the Roman hypocaust heating system can be seen. The museum displays a model of the complex, along with digital reconstructions.
Research: ECPK
reference sources   RRBDNB

Roman Baths, Bath