Surrounded by a forest of conifers that recalls the same typical features of the more famous French grotto, it is reached along a shaded avenue. The grotto was opened in 1912 and, in 1922, a small Chapel was built beside it instead of the imposing sanctuary that had first been considered building: inside there is a fresco depicting Santa Chiara and a triptych with the Immacolata between two angels. The grotto houses a marble statue of the Madonna in natural size. The anniversary falls on 11 August.