Grotto of the Redemption was the second folk-art installation I remember visiting as a child. It was a fascinating place, made completely out of rocks and gemstones by Father Paul Matthias Dobberstein.
It’s said that Father Dobberstein became critically ill with pneumonia. As he fought for his life he prayed to the Blessed Virgin Mary to intercede for him for the grace of health. He promised to build a shrine in her honor of he lived.
And he did.
Official Grotto of the Redemption website