Sanctuary's size and location

The sanctuary of Mercury, located at the summit of the puy de Dôme, covers approximately 3,600 square meters and was built around 140 AD in tiered terraces on a slope of 9 meters. It sits at an altitude of nearly 1,450 meters on a volcano, and is described as roughly half the size of a football field.

Historical discovery and excavation

The sanctuary was discovered in 1872 by Émile Alluard, a physics professor at the University of Clermont-Ferrand, during the construction of a mountain meteorological observatory. Excavation work continued until 1878, uncovering the first traces of a temple dedicated to Mercury, a Roman god incorporated into the local Arverne religious traditions.

Architectural features and restoration

The sanctuary forms a quadrilateral of 62.83 meters from north to south and 60.35 meters from east to west, or approximately 3,600 square meters. The Department refers to it as a "perfect square" of 60 × 60 meters. After more than ten years of restoration, the site reopened to the public in July 2024, following extensive work that included rebuilding parts of the retaining walls.

Cultural and historical significance

The sanctuary attracted many pilgrims, and a settlement for visitors developed at the Ceyssat pass between the first and third centuries, along the Via Agrippa, a major Roman road. The site was classified as a historic monument in 1875, only three years after its discovery. The puy de Dôme has been inscribed in the UNESCO World Heritage list since 2018 under the title of the Chain of Puys and the Limagne Fault.