Every birth, death, and marriage is recorded in these color-coded leather-bound books.

This staircase in a lush tropical grotto was built by enslaved laborers and renamed to honor Queen Victoria's role in ending slavery in the British Empire.

The world’s largest underwater sculpture is found just off the coast of Nassau.

Impressive sink holes fill this untouched old-growth forest in the Bahamas.

Inhospitable caverns just beneath this island paradise offer insights into alien worlds.

Eclectic collection of rare and beautiful stones in a historic home.

The largest riverfront opening cave in the Ozarks.

One of the deepest springs in Missouri.

The world's longest known cave system.

Home of an evil witch famous within southern folklore.

The first full-scale tunnel built in America is short but scenic.

The small cave that housed Tennessee's "first citizen."

More than five miles of underground passageways.

This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

Disney's abandoned animal island is now an overgrown ruin that was almost the coolest attraction ever.

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

This large midwestern cavern features impressive rock formations and an underground waterfall.

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

This cave holds a surprisingly colorful variety of geological oddities.

This seemingly charming home memorializes and honors the victims of a century-old unsolved murder.

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

This mosaic-covered bar is brimming with curated curios.

A kitschy, creepy St. Louis mainstay.

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