The remains of Crystal Palace Great Exhibition of 1851.

A small flooded ghost town with a few scattered structures remaining.

Huge masonic hall in Philadelphia with lavishly themed rooms.

2300-year-old Roman road connecting the empire.

A historic neighborhood church is reborn as a psychedelic arts collective.

San Diego's most historic and haunted home.

One of the ghostly stops along Route 66.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

A historic 1890s architectural masterpiece with an iconic clock tower that, once open to the public, now faces an uncertain future.

400-year-old garden, restored to beauty.

The final resting place to 300 Victorian-era pets hides inside the city park.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

The "Seinfeld" diner.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

Statue of death tucked in the University of Medicine courtyard.

A museum dedicated to exhibiting remarkable outsider art.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

A stealthy Apache hideaway that became the haunting site of a mass grave.