The winter home of millions of migrating monarch butterflies.

This fantastical house shaped like a seashell brings aquatic design to architecture.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

These azure waters were thought to lead to the Mayan Underworld.

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.

The world's only museum devoted to the wonders of fluorescence.

This colorful New Orleans bookstore features rare and used titles, with a specialty in Cajun fare.

This abandoned Civil War fortress is slowly being swallowed by the waters of Lake Borgne.

According to one local tradition, the entrance to the Voodoo underworld can be found in New Orleans through seven gates scattered throughout the city's French Quarter.

This enormous sinkhole hides a secret world created from divine wrath.

This Old West eatery along America's Loneliest Road was originally a stop on the Pony Express.

An 1870s ranch for pioneers, rodeo stars, and divorcees was abandoned and left for dead, until the city reopened it for exploration.

A series of labyrinths in the Nevada desert inspire meditation and calmness.

This central Nevada cave is the spiritual home of ancient and enigmatic pictographs.

An overlooked monument to the celebrity gangster who helped put the sin in Sin City.

This former Mormon settlement is reemerging from the receding waters of Lake Mead.

In the middle of a remote desert town is a surprisingly opulent hotel.

Mysterious meeting place for UFO hunters near Area 51.

Beneath a Virginia City bar is the entrance to an abandoned gold mine.

Mine your own precious stones.

A collection of haunted objects and macabre oddities under one roof.

Water of undetermined depth has attracted rare fish and cult leaders alike.

Preserving the remains of Native American cultures which otherwise would have been submerged behind Hoover Dam.

These banned cigarette vending machines now sell little pieces of pocket-sized art.