The facade of this 16th-century building is decorated with carvings of 300 seashells.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

The ruins of a 2,000-year-old Roman fishing village perched on one of the best beaches in Spain.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

Bacteria and algae give the salty water its bubblegum hue.

Geological storytelling.

Walk the whole Mississippi River!

This Memphis recording studio launched the careers of Jerry Lee Lewis, Johnny Cash, and Elvis Presley.

The winter home of millions of migrating monarch butterflies.

Dating back to the second century, vestiges of prehispanic mural paintings are found in this underground palace.

This Costa Rican topiary park is a surreal garden of unearthly delights.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

The location of the Bridge of Death and the Gorge of Eternal Peril in "Monty Python and the Holy Grail."

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

A close look reveals that the Scottish monument is just slightly off-kilter.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

A remarkable feat of Victorian engineering across the Firth of Forth.