The thermal springs of Roselle have been known since ancient Roman times, as proven by some objects found on the site (two marble lions, for example, stand today against the circular pavilion of the baths). During the Middle Ages, the baths underwent a period of decline, but they were active again at least by the 14th century, as can be seen from a document dated 1334. Dating from the same period is the construction of a mill, which operated only during the winter, driven by the water from the springs. In 1738 Giovanni Targioni Tozzetti stated that, based on the report of a physician from Grosseto, "everything is in bad order". Almost a century later, in 1822, Grand Duke Ferdinand III of Lorraine – who is still today recalled by a memorial stone on the ancient wall of the building – promoted the work of restoring the baths, reopened to the public in the spring of 1824. Entry was free of charge and constant medical assistance was provided. The waters, analysed by the Florentine chemist Giuseppe Gazzeri in the early years of the 19th century, were considered useful especially for treating skin diseases. In spite of their therapeutic value, the baths were short-lived, entering a slow, gradual decline already toward the end of the 19th century. Today a project is being implemented for creating a new Thermal Park that will combine the benefits of the sulphate-alkaline-clayey waters with the pleasure of a relaxing vacation.