In the apse of the church, close to the choir, a grill has been placed in the floor so that visitors can observe the traces left by the first inhabitants, in the first century CE:
- Two hut floors
- A series of holes for posts
- Fireplaces on the floor
At the end of the first century, a villa was built for use as a farm. The architecture of the villa was Roman. A pond and a water pipe date from this era.
On the south side of the apse, step onto the bridge and look through the glass lean-to to view part of the walls of the Gallo-Roman villa.
The villa was abandoned at the turn of the fifth century. A rectangular building was built where the choir stands today. From late Antiquity it was used prolifically as a burial place. Tombs from the funeral basilica are still visible today. The permanent exhibition entitled "Salagon, c’est toute une histoire" (Salagon through the ages) recounts the various uses the site has seen..