One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

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

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

In the world's oldest university is a stunning 17th century anatomical theater carved from spruce.

A slightly creepy gallery of plaster cast models in the same museum as Michelangelo's David.

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

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

The oldest operating pharmacy in the world features 800-year-old recipes.

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.

Pilgrimage site for star-crossed lovers.

Said to be the only museum in the world dedicated to the most classic of all blooms, the rose.

"Holy Wisdom" overlooks the city that became its namesake.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

A striking symbol of the Bulgarian capital.

This historic black and white monastery is one of Bulgaria's architectural jewels.

A patchwork of ruins from various civilizations in one of the world's oldest continually inhabited cities.

The "Little Ones," show Portugal in full miniature splendor.

One of the largest Roman settlements in Portugal.

Buried next to Pompeii, this lesser-known Roman villa was the opulent vacation home of Emperor Nero's wife.

The walls and streets of the ancient city are peppered with penises.

Erotic art covers the walls of the largest ancient pleasure palace.