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

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

A subterranean haunt where wine and homemade biscottis are always on the menu.

A sculpture of a giant man escaping from the depths of the Earth.

A late sculptor's last project was to turn this abandoned cement factory into a castle-themed amusement park.

When Joseph Marconnott died, he had a unique final wish: to be mummified and put on display.

University City's quirkiest resident lives in a park named after its first.

The red brick house where the father of rock 'n' roll wrote some of his classic hits.

A kitschy, creepy St. Louis mainstay.

This spot in St. Louis, marked with a simple sign, has seen more pro baseball than just about anywhere else in the world.

A floating museum that was sunk by a flood and left to rot in the tides.

A plaque on the side of a parking garage marks the burial place of a great Ottawa chief.

A big museum full of little worlds.

An urban forest overtakes what was the greatest failure of utopic urban housing.

Less a museum than a bizarre fantasy world created by artists and engineers.

A chessmaster's dream destination.