It is simply a shrine rewarding your efforts of finding the entry, by resolving the puzzles of Kass. Head to Faron, as indicated in the image down below.
In stormy weather (very common in the area), put down a weapon on the top of the rock. Lightning will strike the objects, destroy the rocks and free the entry: you will simply have to enter and grab one of the elements of the set.
Written by Bastien "Lloyd" Dubosq-Luyer. Translated from French by Millenium.us.org.
