Terme dell'Osa

Terme dell'Osa is a natural thermal spring located near Fonteblanda that discharges water containing high levels of sodium, chlorine, calcium, and magnesium. The water emerges at different points across the site with varying temperatures.

The site appeared in 14th-century records under Siena's control as Balneum Caldanellarum and was later documented in 1430 as Bagno de le Caldane. These historical names show how the location was known and used over centuries.

The thermal waters represent a continuation of ancient Roman practices, where communal bathing served both health and social functions in Italian society.

The location is currently closed to visitors due to unresolved safety and hygiene issues that have prevented restoration efforts since the 1970s. Check locally before visiting to confirm access conditions, as the site remains under assessment.

A local doctor named Deirnich analyzed the waters in 1786 and named them Probatica Piscina after their effectiveness in treating skin conditions. This early medical recognition shows how the healing reputation of the spring was documented and valued.

Location: Orbetello

GPS coordinates: 42.55246,11.17616

Latest update: December 14, 2025 11:26