This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.

Cannon designed to fire an atomic warhead.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

A hermit's tiny cell built into the cliffside that saved him in South Pembrokeshire.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

The strange phenomenon causing gravity to "work backwards" on this hill has been blamed on the paranormal.

Fonts are born and bred here at the oldest letterpress type foundry in the United States.

This woodland architectural installation acts as a camera obscura for the heavens.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

The splendor of this 17th century golden chapel has led it to be called the "eighth wonder of the world."

The world's tallest bridge is also possibly the most elegant.

Rotting dome home spotted near Chapel Hill, North Carolina.

A mysterious echo seems to defy the laws of acoustics.

The world's second largest single-dish radio telescope, once used to contact E.T.

A tiny plaque hidden miles into the Washington wilderness is all that remains to honor a shipwreck that left 18 people dead.

Legends surround this jagged rock formation in the New Mexico desert.

This burial pyramid in central Ireland is thousands of miles and thousands of years away from its Egyptian inspiration.

Seattle’s Whimsical Mural Master.

Providing the soundtrack to the golden years of the Seattle grunge scene.

42nd story Pyramid shaped penthouse tops Seattle's oldest skyscraper.

Pick up all of the cosmic knick-knacks under the sun or take a creative writing course, all offered in this novelty storefront.

Seattle's own bad art museum located inside Cafe Racer.

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