An ancient capital city that dates back 3,000 years old and harbors many surprises.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

A toxic ghost town sitting atop a massive coal fire.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

This massive library holds what was once the largest book collection in the world.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

A bizarre house filled with an astounding array of collections.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

The fairy tale castle of the "fairy-tale king."

Medicinal spa created with the discharge from a geothermal energy plant.

A half-acre utopia in the New Mexico desert features a graveyard, a game of horseshoes, a library, and a mailbox.

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

Down a stairway in the East Village, you could once read a plaque describing an alternate history of a fictional version of Manhattan.

The final resting place of the great escape artist, where some still gather to wait for his escape from death.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

Michael Jackson got Bad and Crocodile Dundee walked on heads in this iconic Brooklyn subway station.

More than 300,000 historical artifacts from the famous music venue, from Duke Ellington's handwritten score to The Beatles' booking slip.

This enormous World War II relic is one of the largest wooden structures in the world.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

The narrowest house in America is seven feet of pure spite.

Once on display alongside a giant Gumby, it’s as tall as a nine-story building when fully extended.

This collection of over 50 classic pinball machines awaits visitors to downtown Roanoke.