The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

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

A trash dump made beautiful by nature's power.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

An old vending machine serves up unpredictable beverages from its seemingly magical insides.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

A snapshot of the city's fascinating voodoo culture.

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

Dramatic river bend surrounds a natural red-rocked pedestal.

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

Most-visited and most-photographed slot canyon in the American Southwest.

On the Oregon coast there is a natural hole that seems to be draining the sea.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

Rippling sand dunes frozen in the Arizona rock.

Non-profit time travel mart sells goods you would need for a trip through the fourth dimension.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

A huge musical instrument played by the ocean.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

The violinist who played on as the Titanic sank is buried in this quiet English cemetery.

A metal tree emits eerie, melodic notes on top of Lancashire's Crown Point.

The view from this giant Stone Age toad is unexpectedly beautiful.

Giant origami sculptures tucked into desert scenery beckon passers-by to explore further.

Cold storage for agricultural biodiversity.