An Iowa priest vowed to build a shrine if he survived pneumonia; after recovering, he spent 42 years using over 100 train carloads of stone to create it

The Grotto of the Redemption in West Bend, Iowa, owes its existence to a young seminarian's promise made during his illness. Initiated by Father Dobberstein, the monumental structure took an astonishing 42 years to complete. Utilizing a variety of geological elements, over 100 train carloads of stones were involved in its construction, making it a celebrated historic landmark and one of the largest man-made grottos globally.