The thermal baths of Caldes d’Estrac, as we now know them, date back to the early 19th century and are publicly owned. The current building is from 1818 and is built on one floor, with a bricked-vault roof.
However, the first spa that we know of dates back to 1396, authorised by the Consell de Cent (Barcelona’s municipal government of the time), and was probably built on the remains of the old Roman baths, which were located under the current Town Hall and which is also where archaeological remains from Arab times were found.
There is a document signed by King James II in Caldes in 1312 according to which the King went there for a cure and; and another, of 1319, in which the King had Queen Mary go to Caldes following her doctors’ advice. Another king who stayed there was Alfonso III, who visited the baths on several occasions in 1335.
In 1766 the rector Francesc Sanz built eight baths, four on each side of the corridor. In 1794 a drop in water level made it necessary to fit a lift pump and build lower baths.
The water comes out at a temperature of between 37.9 and 38.8 °C, it is mesothermal and hypotonic with medium mineralisation, and is suitable for chronic disorders of the musculoskeletal system, osteoarticular trauma and the respiratory system.
Next to the public baths is the thermal water spring, where people traditionally fill bottles and containers for domestic and culinary use.