The Lead-Lined Chamber of the Sulis Spring

Since 1978, these waters have been known to contain Naegleria fowleri, a deadly pathogen. This was identified after a tragic death from naegleriasis in the nearby former Beau Street swimming baths, which were fed from the same hot spring complex. Today, while the site remains a major tourist attraction, visitors can tour the baths and museum but cannot enter the water due to the presence of the pathogen.

Rain strikes the Mendip Hills and travels through limestone aquifers to depths of between 2,700 and 4,300 metres until it bubbles up from the ground. Roman engineers, possibly under the instructions of Emperor Claudius, drove oak piles into the mud to provide a stable foundation and surrounded the spring with an irregular stone chamber lined with lead. This allowed for the development of a bathing complex that included a caldarium, tepidarium, and frigidarium, which functioned until the Roman withdrawal from Britain in the 5th century.

The site is a layered history of worship and architecture. It features a Roman temple constructed between 60 and 70 AD, a sacred spring dedicated to the goddess Sulis, and 19th-century buildings at street level. Among the archaeological treasures are 130 curse tablets discovered in the sacred spring in 1979/80. Many of these tablets contain curses related to the theft of clothes while people were bathing in the waters.

Visitors can still explore the ruins today by touring the museum and the various bathing features. For those who wish to experience the thermal waters safely, the nearby Thermae Bath Spa and the refurbished Cross Bath offer modern bathing facilities. These sites use a series of more recently drilled boreholes to provide a clean and safe supply of spa water for modern bathers.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons