The name of this tiny pocket park tucked between two buildings on Manhattan's Upper West Side is Latin for its location: "seventy-one."

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

There are owls with glowing eyes in Herald Square.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Elevated freight railway turned wildly successful urban park.

A Prada store in the West Texas desert that is never open for business.

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

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

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Once close to extinction, there is no shortage of elephant seals on the beaches of Año Nuevo State Park.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This historic national park is covered in the stunning ruins of red rock pueblos.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

These pretty kitties killed and ate as many as 135 railway workers.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

Four-story concrete hotel never opened to customers.

The king of U.S. high points towers over every other peak on the continent.

This trio of Australian rock spires may have inspired aboriginal legend or just modern tourism.

A massive stairway that almost wasn't leads to one of Australia's most scenic vistas.

Come for the flowers, stay for the bats!

The largest collection of Indigenous Australian artifacts in the world, and the rare museum where wood-and-glass cabinets have trumped interactive exhibits.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.