The symbol was surreptitiously built into the river bank by German prisoners of war.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

The house's confection-like decorations are the result of one man's painstaking work over decades.

A giant "X" symbolizes the blood spilled from the brutal Juárez drug wars.

A Bhutanese temple gifted from the isolated Himalayan kingdom is now a surprising cultural gem located at the University of Texas at El Paso.

An abandoned amusement park based on the popular 1940s Red Ryder comic strip.

The world's first commercial spaceport is a disappointment of cosmic proportions.

This quirky hot springs town known to locals as "T or C" was named after a radio show.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

A burnt-out motel with priceless Native American artwork in the basement, redeveloped into apartments.

This futuristic airport terminal was abandoned for decades before reopening as a hotel—with a vintage plane of its own parked out back.

There aren't too many operational funiculars around, but Pittsburgh has two!

Hundreds of caves once used to store grains and animal feed.

An experimental, community court opened in 2000 takes a new approach to youth offenders in south Brooklyn.

An unconventional space for art and science housed in a massive old warehouse.

A community farm in the midst of the Brooklyn concrete.

The most unloved grain elevator in Brooklyn was a “Magnificent Mistake.”

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.

There must be a pun in this haystack somewhere...

A replica of a 7th-century church hides in plain sight in the middle of the concrete jungle.

A small part of lower Manhattan is actually made from a bit of England.

The world's oldest hologram gallery and the labyrinthine laser laboratory of a holography pioneer.

Three stories above you, your salad is being grown.