Cascate del Mulino, Saturnia
Must-DoIconicItaly's most famous free hot spring — sulphurous water cascading over white travertine terraces. Open 24/7, 365 days. Free parking (arrive early on weekends). The water is warm enough to swim in winter.
Bagni San Filippo
Must-DoA white "whale" calcium formation in the Val d'Orcia forest with natural hot pools below. Hotter than Saturnia and far less crowded. 10-minute walk from the village car park. Stunning in every season.
Sorgeto Bay, Ischia
Must-DoVolcanic water bubbles through rocks directly into the sea. Create your own perfect-temperature pool by mixing hot and cold water. Access via 234 steps or by boat. Free and open 24/7 — spectacular at night.
Terme di Petriolo
Hidden GemHot sulphurous water flowing into the Farma river between Siena and Grosseto. Medieval bath ruins on the bank. The hot/cold mix in the river is incredible. Very few tourists. Free parking roadside.
Terme Libere di Bormio
Hidden GemWild hot springs near the ski resort town of Bormio, fed by the same source as the famous Bagni Vecchi. Small natural pools in a mountain stream setting. Especially wonderful in winter with snow around you.
Pozza dei Bagni, Sardinia
Hidden GemThermal pools near Fordongianus in central Sardinia, where hot water surfaces beside the Tirso river. Roman baths ruins nearby. Almost completely unknown to tourists. Free access.
Our pick
Saturnia at sunrise for the Instagram moment. Bagni San Filippo for the hottest water and fewest crowds. Sorgeto at midnight for pure magic.