The warmest cave in the Ozarks features two seemingly bottomless lakes.

The only diamond mine in the world where you can keep what you find.

A kitschy, creepy St. Louis mainstay.

Community bookshelf of 25-foot-tall book spines.

The show pony of cave systems, Fantastic Caverns manages to live up to its name.

The world's largest man-made underground caverns offer unparalleled underwater wonders.

The history of the treatment of mental illness, illustrated in all its gory detail, and housed in an asylum.

New York's oldest magic store.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This midcentury LA bar was the birthplace of tiki culture.

Antarctica's bustling metropolis, originally established by Richard E. Byrd.

If Hello Kitty were Mickey Mouse, this would be Disneyland.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

The first permanent memorial to a unique secret weapon of World War II.

A spiritual vortex among the red rocks in Sedona.

Statue in Salem of the woman who starred as the witch Samantha in the sitcom "Bewitched."

Always a new use for this old building.

Craft liquors concocted in an old Seattle warehouse.

Allowing humans and fish alike to migrate from freshwater to saltwater and back again.

Couple's personal collection of pinball machines turned public pinball museum.

An old vending machine serves up unpredictable beverages from its seemingly magical insides.