A remnant of the original World Trade Center complex continues to serve as a commuter gateway.

This cathedral hides a sculpted dog that determines your fate and an unexploded shell from World War II.

Massive galleon from a box-office bomb docked in Genoa.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

Destroyed numerous times, this centuries-old bridge has always been rebuilt with its original design.

This centuries-old Italian chapel hangs midway down a sheer cliffside.

One of the most well-preserved castles in Italy also contains a rare medieval example of a port fortification.

This winding road through an Italian canyon may be the most scenic drive in the world.

This Italian foot path winds through the mountains via 52 individual tunnels.

The sinister ruins of one of the worst dam failures of the 20th century lie in this astonishing alpine setting.

After serving in World War II and picking up Apollo astronauts, this aircraft carrier has been turned into a museum overlooking the San Francisco Bay.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

A decommissioned Naval base now rents itself out for people who want to blow stuff up.

This stretch of beach along California's central coast is a busy highway for the largest seal in the northern hemisphere.

A massive volcanic plug is now a protected area that hosts a number of bird species.

One of the world's tallest Ferris wheels takes visitors high above Las Vegas in a spinning party room.

Don't blink or you'll miss it.

A classic Route 66 landmark that was built with scrap lumber and is held together with kitsch and puns.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Most-visited and most-photographed slot canyon in the American Southwest.

A sharp bend in a dramatic river canyon cut through red rocks.