This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.

The Sighignola summit on the Swiss border offers views so breathtaking it's been named one of the most beautiful places in Italy.

This sublime architectural marvel is a rare example of an expressionist church.

A meandering boardwalk across the bogland leads to a "stairway to heaven" with sublime views.

Far from the shore, this sandy victim of the Skeleton Coast looks like it was plopped in the middle of the desert.

The ancient necropolis houses the immense rock-cut tombs of four Persian kings.

A stone circle on the slopes of a Caribbean volcano commemorates the leader of an anti-slavery uprising.

An abandoned Byzantine fortress and notorious prison.

The weathered grave of a medieval anchoress who walled herself up in a cell attached to a church.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

Western Europe's only representation of a Roman goddess still in its original location sits in an unassuming park.

A backdoor to Machu Picchu that only the most foolhardy infiltrator would attempt to breach.

The world's fifth tallest waterfall is a spectacular silver chute of water that cuts through the cloud forest in northern Peru.

This 700-year-old Cyprus castle is the birthplace of the world's oldest wine, said to be toasted by Richard the Lionheart at his wedding.

With nearly double the depth of the Grand Canyon, this Peruvian canyon is one of the deepest in the world.

A pride of the state, this working museum crafts pottery mosaics in the style of Pennsylvania's earliest European settlers.

Eccentric concrete mansion and museum designed and built by hand from the inside out.

At the United Kingdom's only residential library you can sleep among the books.

The vertical-axis windmills of ancient Persia have been grinding flour for 1,000 years and counting.

Every winter, the wind carves blocks of frozen water into beautiful abstract shapes inside this unusually curved tunnel.

These ancient sunken lanes were naturally tunneled into the soft ground by countless footsteps.

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

A 1,500-year-old, 3-story subterranean city where ancient Persians took refuge in times of war.