Plan of the water network

Approximately ten kilometers of underground galleries, built by the Gallo-Romans,
have been identified under the village: they are proof of the Romans extensive knowledge of hydraulic engineering. Oriented
mainly to the west and north, the galleries have been found up to a depth of 12 meters; they were
equipped with over 300 access shafts, some of which are indicated on the map above. The major,
natural stream is the one that flew along the Basilica (on the map: Basilique) towards the 'sacred source'
W of the church (Eglise).