In the 14th and 15th centuries, the municipality of Caldes was ruled over successively by the Montcada and Cruïlles families from a castle so original that it contained some fully functioning Roman baths. In fact, the Roman building formed part of the structure of the fortification.
In the 19th century, the dismantling of part of the castle, which in the modern period had been turned into a third-rate hospital for the poor, could not be completed because of the Roman baths, which had to be preserved. Furthermore, some of the castle’s rooms had been converted into private dwellings. As such, the entire western section of the castle walls has been preserved, fortified with three towers. It now shelters the Roman baths and an adjacent municipal building, currently being refurbished, which also originally formed part of the castle.