Mentioned in 1069 during a donation to Montmajour Abbey, Saint-Jean-du-Grès is the former parish of Fontvieille. Initially part of the possessions of St.-Victor de Marseille, it was the village's only parish until the 17th century.
ATTENTION - PRIVATE PROPERTY
Originally a Romanesque building, only the apse remains. In 1069, the monks of Montmajour took possession of it. It served as a parish church until 1768, when Saint-Pierre-ès-Liens was consecrated.
The chapel is located on the Mas Saint-Jean olive estate.
A small building with a rather unusual appearance: four large flying buttresses support the side walls. A small semi-circular apse closes off the nave. The barrel vault covering it rises more than 8 metres. A stone bench runs along the entire length of the nave walls. On the north pilaster of the triumphal arch, the dedication of the church to Saint John the Baptist and Saint John the Evangelist can still be seen. The entrance, now on the east side, was originally through a door in the south side, which was later closed off. Three steps lead up to the stone altar, decorated with two statues of Saint Peter and the Virgin Mary.