The village of Saint Cyr, located on the old shore of the Gulf of Machecoul, is the original parish of the current town of Villeneuve en Retz, it dates from Roman times.

Founded by the lords of Noé Briord in the 13th century, the history of Saint Cyr is linked to the sea, and in particular to its withdrawal due to the siltation of the Marais Breton.

After a fire destroyed the first construction of 1262, the church of Saint Cyr was rebuilt thanks to subscriptions from the inhabitants of the village. It is considered today as one of the three prettiest in the region. Its many openings through the stained glass windows that surround it give it a particularly bright atmosphere.

Its bell tower is located on the north side of the choir for concerns of stability of the basement. The building, like the many monuments located on chist soil, possitioned to catch the sea wind, requires special monitoring.

A guided tour of the church is possible during heritage days in September.