The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

The U.S. Navy’s preposterously detailed mini battleship took 77,000 hours to complete.

Romans built the world's tallest artificial waterfall in 271 BC.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

The smallest post office in the United States is no bigger than a broom closet.

A time capsule of Floridian history fights to survive on the banks of Chokoloskee Bay.

Ming Dynasty necropolis raided during the Cultural Revolution.

The most famous location in China was home to whole dynasties worth of imperial rulers.

This ancient Chinese observatory still contains early astronomy technology.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

A son-and-daughter meat market, hawked by mom and dad.

This psychedelic tourist trap is a leisurely descent into madness.

The once highest point in China blends symbolic design with a kick of adrenaline.

An out-of-place slice of France, smack in the middle of Shanghai.

A giant scale model giving a sneak peek at what urban planners see for Shanghai by 2020.

The site of the first "historically true" UFO encounter in the U.S.

A World War II-era submarine is stuck in the mud in New Jersey.

Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

This one-of-a-kind archeological site is home to strange prehistoric ruins, the original use of which is still a mystery.

A Medieval Water Tower in the Heart of Massachusetts.