Bringing a stone to the camino

[Richard Ferguson]

I spoke to a German pilgrim, who told me of the tradition of bringing a
stone from home on the pilgrimage, symbolizing one's sorrows.  He said
that there was a place on the pilgrimage, maybe a tall hill, where
pilgrims have left these stones for centuries.  For him, this experience
was the most moving part of the camino.

What is the name of this place and where is it located?  Thanks.

Richard Ferguson