Situated on the Pène mountain range above a crossing point in the Vallée des Baux, the site of Castillon has throughout history taken advantage of its dominant position over the marsh and the traffic routes.
There was an early oppidum in the Protohistoric period, followed by a settlement in the Hellenistic period. The Romans left a few traces here before abandoning it in part.
From the 11th century onwards, the site acquired a new importance when the Lords of Les Baux incorporated it into the defensive system of their territory. The castle was supported by 4 towers, three of which are still visible. There were 40 households. The lord of Les Baux had the castle chapel of Ste-Marie-de-Castillon built there.
The site was abandoned in the 14th century without any trace of destruction, and was used as a ‘quarry’ for the extension of the village of St-Martin-de-Castillon.
Elements of the excavation of the site can be seen in the hall of the village hall.