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

A bizarre house filled with an astounding array of collections.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

Hot springs monkey spa in the middle of Hell's Valley.

A 140-year-old castle with underground caves hidden in San Francisco.

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

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

A one-of-a-kind collection of a unique medium.

A church of bones, decorated with 40,000 human skeletons.

Dramatic river bend surrounds a natural red-rocked pedestal.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

This faux-seedy Japanese arcade is made up to look like a maze of alleys straight out of a cyberpunk dystopia.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

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

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

World's first "penitentiary," meant to be humane, drove men insane.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

An ancient city hidden in the heart of the Sierra Nevada mountains.

Hundreds of stones dangle from barren trees in the middle of the desert.

Puffin enthusiasts flock to Europe's largest seabird cliff, which over one million birds call home.

A giant concrete orb in far north Iceland marks the ever-shifting boundary.

The oldest hall in Iceland was written of in the Sagas and features a centuries-old escape tunnel.

Two volcanic lakes in an enormous crater formed in a prehistoric eruption.

Strange rock formations tower above the river that snakes through this enchanting Icelandic canyon.