A feature of Bagno Vignoni, besides the thermal water, is the structure that remained unchanged in the time. In fact, the village square isn't as we can imagine in other places; on the contrary it is made of boiling water that gushes out at 52°C. In fact, the thermal water tub is the square center, which is closed on three sides by an about one meter and a half-high boundary wall. Around it there are some buildings designed by Bernardo Rossellino in Pius II's honour and the arcade where Santa Caterina da Siena stopped.