The picturesque little chapel of Notre dame des Grâces–isolated on a southern summit of the village–is surrounded by a cemetery and is what is left of the primitive church of Hour. The construction date of the church is not known, but we do know that it had three naves. The chapel was built on the location of what once was the church choir.
It is thought that the church was destroyed around 1553 by the troops of Henri II who had allied with the Germans protesting against the troops of Charles Quint.
In Celtic times, there was a Pagan alter here, with an oak tree and a cemetery, and during the 7th century, an oratory dedicated to Saint Martin, with a linden tree and a cemetery. The first parochial church–with three naves– was initially dependent of the abbey of Stavelot in 842, then later of the abbey of Leffe in 1282.
In 1856, a new church–the church of Saint Martin–was built and the former church was demolished. The choir was conserved and became the chapel of Notre dame des Grâces.