A creepy steel gremlin has protected the Bay Bridge since 1989.

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

This stunning gothic ruin was a casualty of the Indiana steel industry crash.

The very first subway station in New York City is beautiful, decked out in chandeliers, and ... abandoned?

The first "Hall of Fame" in America was designed by legendary Gilded Age architect Stanford White for what was then the NYU uptown campus.

A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

One part local history, 99 parts gruesome haunted house.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

The world's smallest park was dedicated in 1948 as the only colony for leprechauns west of Ireland.

The magic's in the hole!

A giant Troll lurks under one of Seattle's oldest bridges.

See massive fossils that are over 200 million years old in northeastern Arizona.

Beautiful steampunk ghosts of early Massachusetts.

The world's largest piece of copyrighted artwork.

Macabre astrological automaton clock dating to the late 1400s.

The most visited, and possibly most controversial, museum in Germany.

Cold war icon and onetime "hole" in the iron curtain.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

This wrecked airplane has been sitting on a black sand beach since the 1970s.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

Lie in a hammock where George Washington stood.