What is the origin of the Saturnia hot springs?

The origin of the hot springs of Saturnia is geological, even if legend attributes it to a bolt of lightning from Jupiter. According to the most widespread account, the god hurled lightning at Saturn; it struck the earth and made a hot spring gush forth. It is a myth, not the explanation of how the baths formed.

In reality, rainwater seeps into the subsoil, where it circulates for a long time and warms up before rising back to the surface. It gushes out at around 37.5 °C and notably contains sulfur compounds, responsible for its characteristic smell. The spring also feeds the Cascate del Mulino, the natural pools visible near the village. The water flows there continuously; its temperature may seem mild rather than scalding, especially when the air is cool. This natural origin explains the water's warmth and composition, but it does not mean that bathing cures an illness: for a health issue or a pregnancy, it is best to seek advice from a professional before entering.