The St Barthélémy's Chapel is the oldest chapel in Nendaz. The exact date of its construction is not known, but a document from 1447, signed by the Bishop of Sion, mentions that 40 days of indulgence would be granted to anyone who gave a donation to the chapel, which suggests that the building predates this date.

Before the construction of the dam, the St Barthélémy chapel was located in the Cleuson valley, on the right bank, slightly upstream. Built of wood, it was renovated several times, the last time in 1888. In 1951, the dam workers built a new stone chapel on the present site.

The St. Barthélémy Chapel has long been an important destination for processions. The inhabitants walk from various villages of the district, some of them for long hours. The cheeses from the various mountain pastures in the region are blessed during the service on 24th August every year.