This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Abandoned railway line circling the city of Paris.

A pub that is literally in the middle of nowhere, but continues to do business.

This cramped crevasse saw the entire population of its island suffocated inside its depths.

This once-majestic, now-abandoned Victorian castle has seen better days.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

One man spent 10 years building a spectacular section of road because no one else would.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

These fantastically named natural pools look like something out of a Scottish myth.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

The United States Capitol's former columns still stand.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The hidden lair of an alchemist rediscovered in a 2002 flood.

Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

The largest drain hole in the world.

The largest greenhouse in the world is home to over one million types of plants.

A Victorian Gothic masterpiece housing a world-class collection of rare books and manuscripts.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

This former abandoned hospital, a complex of stunning 19th century buildings, once housed 2,000 psychiatric patients.

This submersible road connecting a French island to the mainland is lined with safety towers for when the tide strands travelers.

This unique temple complex remains off the typical tourist trail.

Crooked windswept pines give this old forest an enchanted and magical look.