Archaeologists working in the basement below the 18th-century Bath Assembly Rooms, have revealed the remains of a rare cold bath.

The excavation was part of a major project by the National Trust to restore the rooms and create an experience that will transport visitors back to the social scene of Bath in the late 18th and early 19th centuries.

At that time, assembly rooms were a popular place for entertainment, conversation, dancing and gambling in many fashionable towns across the country.

Bath, amongst other spa towns, was known for its hot mineral water and became a popular spot for ‘taking the waters’. In the 18th century, medical practitioners also recommended cold bathing for men and women as beneficial for various physical and mental ailments, including gout. They advised regular, if not daily, bathing by plunging into cold water for a short period of time and then warming up quickly afterwards.

There was a surge in plunge pools and cold baths in private houses and estates along with public facilities in Bath and other towns, however the location of the one at the Assembly Rooms suggests it would have been more exclusive, and for those wanting a more private cold bath experience.

The Bath Assembly Rooms were built between 1769 and 1771 by John Wood, the younger, who would have been heavily influenced by medical theories. The New Bath Guide of 1778 noted “…a commodious cold-bath, with convenient dressing-rooms,” and there were rooms for billiards, coffee and gambling along with spaces for balls and concerts, making it a ‘one-stop-shop’ for all leisure, health and entertainment needs.

The excavation involved removing a later floor that had been installed over the Cold Bath and removing tonnes of rubble to reveal the historic steps down into it, and its finely joined stone walls, as well as a niche which would have held a statue or sculpture.

During the Second World War, the Assembly Rooms were bombed, and the Cold Bath suffered damage. In the years after the war, the bath was filled in with rubble and a floor laid over the top, although research suggests a floor may have been laid over as early as the beginning of the 20th-century and the space used for storage.

Tatjana LeBoff, National Trust Project Curator explained: “There are many elements of this discovery that are still a mystery. The Cold Bath at the Assembly Rooms is highly unusual. It is a rare, if not unique, surviving example, and possibly it was the only one ever built in an assembly room.”

She continued: “Whilst our records tell us about a variety of people who were employed at the Bath Assembly Rooms in the 1770s, none of the records mention anyone being employed to attend the Cold Bath. Nor are there records of bath sheets being hired or bought or any laundry service for them, so perhaps the bather would have brought their own towels and servant to help with bathing and dressing.

“It is unlikely men and women of status would have used the Cold Bath together so there could have been different days or times when they were available to each. We are

still researching records, letters, diaries and other documents to see what more we can find out that will help us piece it all together.”

Bruce Eaton, Archaeologist at Wessex Archaeology, said: “Although historical records indicated that there was a cold bath buried beneath the Bath Assembly Rooms, we had no idea what preservation of the bath would be like. The building suffered damage at the hands of the Luftwaffe and the rooms were remodelled in the late 20th century but, after carefully excavating tonnes of concrete and rubble, we saw the original structure emerge in its entirety.

“It’s tremendous to be able to piece together this rare archaeological evidence of an 18th-century cold bath with social historical accounts from the time – a fantastic result for the National Trust and visitors to the Bath Assembly Rooms.”