The thermal spa building of Casciana, established by Montefeltro in 1311 and renovated after two centuries by the Medici family, got its present day layout in the 1800s, starting with the work ordered by Grand Duke Ferdinando III. The beautiful Neoclassical style of the thermal spa's facade built in 1870 was based on a plan by the architect Poggi, known as the designer of Piazzale Michelangelo in Florence.