La pierre levee Pontils regarde des attics et aux aux caves du roi - taken from Franck Marie's Etude Critical Rennes-le-Chateau. And actually this is the view seen - which is the same view allegedly seen in the second version of Poussin's Les Bergers des Arcadie! It would be from the Menhir of Peyrolles, 150 meters from the Poussin tomb!
This is the area observed from the vicinity of the Menhir of Peyrolles in reality.
This mythology around the Menhir of Peyrolles/Boudet has its own history. You can read this HERE.
Sicard writes: Peyrolles Menhir -- (Often attributed to Arques). By following the road that leads from Couiza to Arques, on the territory of the commune of Peyrolles, and arriving at the kilometre marker [borne] 65.5 km, if you turn to the left, you will see a megalith that stands about 150 metres from the road. This stone is made of ancient limestone: it is inclined SS W.. and only rises above the ground by 2metres 50. Its greatest width is 0.75 metres and its thickness is 0.60 metres. This monument is at the place called Les Pontils, on uncultivated land. (It is claimed that there is a natural or artificial cave under the megalith (Note de abbé Ancé).