Pilgrimage site for star-crossed lovers.

Found down a long dirt road, a sacred Mexican cenote and 18th-century hacienda remain hidden.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

This fountain was designed to honor the man who helped bring water to Barcelona.

Walk into an underground archeological dig, the site of the Roman Forum that was once the center of Valencia.

With a facade that measures just 107 centimeters, this five-story building is one of the skinniest in Europe.

Vibrant street art created with mixed media.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

This ex-prison dates back to the Middle Ages.

Explore the complex ecology of this multifaceted nature preserve by riverboat.

After Christopher Columbus died, his son built a fancy house to rule from.

The final resting place of Christopher Columbus - or possibly someone else.

This trio of Dominican cave lakes comprise a colorful biosphere of natural life.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

One of the oldest and most significant collections of Ancient Egyptian archeology outside of Egypt.

The intricate geometry inside this Baroque-style dome was designed to create "terror of the human soul."

Now an entertainment complex, the Lingotto building was once an avant-garde auto factory with a test track on the roof.

A fake medieval village in the middle of Turin.

The astonishing collection of an infamous criminologist.

Real bones which are said to have belonged to a Polish dragon.