Looking at the 1813 cadastral map the other day (as you do) I was drawn to the area around the Chapelle de Tous les Saints.
The chapel is in the top left corner of the the old cemetery, the area outlined in yellow.
The area outlined in red is part of the new cemetery
We know that the area to the east and south of the chapel was the burial ground, which was moved to its current location at the start of the 20th century. The exact date seems to be lost in the mists of time, although there must be a record somewhere.
What interests us is that on the 1813 cadastre an old cemetery is shown: the cemetery which predates our current "old cemetery". It's marked on the map as the Ancien Cimetiere (bottom left corner of the above map), in a location now occupied by houses and farm buildings.