Bagni San Filippo

At Bagni San Filippo, thermal waters feed the Fosso Bianco through woodland near Monte Amiata. Pale travertine terraces and natural pools give the stream its distinctive appearance.

Why it matters

The site makes the formation of mineral deposits visible in the landscape. Calcium-rich water builds up stone over time, linking the springs with the wider thermal environment of the Amiata area.

What to notice

The Balena Bianca, or White Whale, is the largest and most recognisable formation, named for a profile resembling a whale's open mouth. Smaller terraces and basins follow the stream through the trees. Differences in flow, deposition and water conditions create variations in the surfaces and colours of the pools.

Context and history

The hamlet belongs to the territory of Castiglione d'Orcia. Its springs and mineral formations connect the settled landscape of the Val d'Orcia with natural processes that continue to shape the wooded stream. Successive layers of travertine record that ongoing interaction between warm water, dissolved minerals and the terrain.