Grotto of the Blessed Virgin Mary at Our Lady of Mount Carmel Monastery


Polish monks built a series of trippy, fluorescent shrines at this Carmelite monastery hiding in suburban Munster. First came 250 tons of sponge rock that the friars used for the grotto's dark, twisting, three-story caverns. Then came the bright-hued bits of rose quartz, blue fluorite and other minerals that glimmer in starry designs from the walls. The real eye-popper is the Fluorescent Altar. Flip the light switch and the stones around Mary's statue jolt to life (a natural illumination effect).

More ultraviolet goodness radiates in the nearby Grotto of the Sepulchre where there's a shrine to Jesus raising the dead.