A wonder of natural limestone formations etched by millions of years of natural interaction between rainfall and rock and air.

This massive water spout has been luring visitors for hundreds of years, some to their death.

Come for the flowers, stay for the bats!

This trio of Australian rock spires may have inspired aboriginal legend or just modern tourism.

An unphotographable nightly march of tens of thousands of "fairy penguins" from sea to shore.

This historic observatory contains the world's oldest refracting lens telescope.

Nine limestone rock stacks on Australia's "Shipwreck Coast."

A clear example of the process of erosion in action.

The tallest sea cliffs on the Southern Hemisphere are a climber's worst nightmare.

The only pollutant in the clear blue water is sunscreen.

A massive stairway that almost wasn't leads to one of Australia's most scenic vistas.

This gracefully curving formation looks like a massive wave that was suddenly turned to stone.

A castle hand-built by a Spanish dreamer in the Australian tropical jungle.

An abandoned railroad tunnel is now filled with bioluminescent bugs.

This deconsecrated church has seen many uses, from a tobacco storehouse to a cinema.

A local student's chance encounter with Keith Haring led to the creation of one of Europe's largest murals.

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

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

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

A lover's walk between hilltop towns, decorated with graffiti love notes.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.