An exceptional peat bog, 12,000 years old
The Creusates peat bog in Saint-François-de-Sales is a veritable natural monument. Situated at an altitude of 1,320 metres, it was formed in a karstic depression resulting from a collapse, slowly filled in by clay and then colonised by sphagnum moss around 7,000 years ago. These mosses accumulated successive layers of organic matter, forming up to 11.5 metres of unbroken peat, making it one of the deepest peat bogs in the French Alps.
A veritable climatic archive, the peat preserves pollen and plant elements buried since the end of the last ice age, tracing 12,000 years of climate and landscape evolution. Listed as a Natura 2000 site and protected by a prefectoral biotope decree since 1985, the peat bog can be visited along a secure interpretation trail, punctuated by footbridges, an educational lookout point and explanatory panels, allowing visitors to explore this sensitive ecosystem gently, without being trampled.
