Les Causeurs, Neolithic menhir archaeological site in Île-de-Sein, France.

Les Causeurs consists of two upright granite blocks standing near the island's church at Place François le Sud, reaching heights of 2.30 and 2.80 meters. These stones form the main features of a Neolithic archaeological site.

The two menhirs are granite blocks measuring 2.30 and 2.80 metres. At the end of the 19th century their removal was considered for the construction of the new Saint-Collodan church, but they were kept in place. They have been classified as monuments historiques since 1 April 1901.

Seen from the side, the two stones look like figures talking to each other, which gave them the Breton names Ar Fillistérien ("the talkers", distinguishing the small talker and the big talker) and Ar Prégourien ("the preachers").

The site sits in the center of the island and is easily accessible on foot from the harbor. Since the location is open and unobstructed, visitors can explore it freely throughout the day.

Local tradition held that placing nine pebbles wrapped in cloth at the base of the stones could cure fever. This practice reveals how the site was intertwined with folk healing beliefs in the community.