The Saint-Symphorien church in Grézac, which depended on the Abbey of Saint-Eutrope, was built in the 12th century. Unfortunately, only the north apse remains from the Romanesque period. The rest of the building dates from the 14th century. The decoration of this Romanesque apse is remarkable: one can admire in particular the beautiful capitals of interlacing and foliage. Despite its simple plan, the church is original in both its design and decoration.
Under the right apse, a vast crypt-ossuary is preserved, its vaults resting on benches arranged along the walls of the room and rising five meters high, resting in the center on a column. The latter bears a capital sculpted with monster heads and grimacing faces. At the base of the ribbed vaults, beautiful corbels and corner columns are sculpted with human faces or floral motifs.
The façade, whose iconographic arrangement is not original, is composed of plaster reliefs. One of them depicts four figures evoking the condemnation of Saint Symphorien to martyrdom. The latter was beheaded. Another depicts a Sagittarius brandishing his bow and chasing a deer. A third depicts two episodes from the well-known fable of the Fox and the Stork, which can be found on two capitals on the south façade of the church of Cozes.
The interior of the building is striking, particularly the northwest corner, which houses a plaster high relief likely dating from the 19th century. All the figures taking part in the scene of Christ's baptism are depicted almost life-size.