Terme di Casteldoria

The Terme di Casteldoria are thermal resurgences along the Coghinas River, on the border between Viddalba and Santa Maria Coghinas in northern Sardinia. Hot, mineral-rich water rises through the sandy banks just a few meters from the river—at the source it can reach around 70°C, so soaking is usually done where it mixes with cooler river water.

Using your material: in 1973 surveys of the Coghinas riverbed identified a broad thermal belt with temperatures of about 68–75°C, linked to a fracture system associated with the Santa Maria Coghinas fault cutting porphyritic granites, likely responsible for the geothermal upwelling. The waters are notably saline (~5 g/L), dominated by alkaline and alkaline-earth chlorides; in 1976 the springs were managed by the Ente Autonomo Acque Minerali.