Wish I’d visited Wonder Cave in time to include it in Wisconsin Underground: A Guide to Caves, Mines, and Tunnels In and Around the Badger State.

Rudolph Grotto Gardens and Wonder Cave fulfilled Fr. Philip Wagner’s promise to Mary, years after he experienced a healing at Lourdes. Construction of the glass- and tile-embellished rock grotto began in 1919. A single corkscrew-like passage with several stairways begins near the bottom of the man-made mound and winds to the top and back down before exiting on the other side of the rock mound. The low, narrow one-fifth mile pathway passes by numerous niches and alcoves filled with statues and religious messages.

Location: Rudolph, Wisconsin (near Wisconsin Rapids). Cost to tour cave: $3; no cost to tour gardens.