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

Constructed in 1892, this Hinesville jail is now an art gallery.

A grandiose octagonal home crowned by a large dome stands out among the antebellum mansions.

Built following the War of 1812, this fort has withstood hurricanes for centuries.

Rusted and decayed, this former mining site is a portal to the past.

A museum devoted to osteopathy and its creator, Andrew Still.

During the 19th-century, this park was a vital trading fort.

Two hundred tons of pioneer artifacts were painstakingly recovered from a shipwreck at the bottom of the Missouri River.

The ruins of a 19th century shelter run by the Independent Order of Odd Fellows.

A kitschy, creepy St. Louis mainstay.

A remarkably opulent mansion with a tragic history.

A big museum full of little worlds.

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

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

The world's largest collection of fine-scale miniatures and one the nation's largest collections of antique toys.

A historic house in St. Louis was plagued by a series of suicides committed by family members involved in a successful brewery.

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

European castle ruins in an American state park are actually the product of death and grief.

At the "Garage Mahal" in Houston, car culture is about more than just driving.

A health museum containing a 27’’½-foot intestine.

Collecting 700 years of mechanical death-dealing, the NRA's sprawling gun museum is a revealing testament to the American obsession with armament.

This historic mansion was built as a symbol of love between a husband and wife.

A historic coal mine that doubles as a museum and tourist attraction.

Home of a 28-foot tall stalagmite known as the War Club.