Grand Jardin

This is the dry valley (called Grand Jardin) around which the Gallo-Roman conurbation was organized.
One of the unusual aspects of the Grand site is the presence of an extensive underground network of hydraulic galleries.
Research, particularly that carried out by J.-P. Bertaux, has been enabled the identification
of around fifteen kilometers of ducts, as well as over 300 wells or access shafts whose function
appears to have been to enable the construction and maintenance of these subterranean passages. All the
galleries seem to converge towards the centre of the Gallo-Roman conurbation (the current church site),
at the presumed location of the resurgence which converges here along with the surface
water (the 'sacred source').