This museum houses two of Mexico's most impressive Aztec monoliths.

Come face to face with the ferocious visage of the serpent-headed mother goddess of the Aztecs.

In Coyoacán, a pair of coyotes crown a public fountain in reference to the ancient Aztec name of the borough.

This "City of Books" holds a museum, library, and the complete personal book collections of five of Mexico's greatest thinkers.

Inside a busy metro station, an impressive mural depicts the prehispanic city of Tenochtitlán.

These spectacular, symbolic serpents lie within the shadow of the Great Temple.

Many people don't realize there’s a lot going on in—and below—the world’s tallest triumphal arch.

This strange sculpture of a menacing skull surrounded by sun rays was discovered at the foot of the Pyramid of the Sun.

A disquieting Aztec sculpture displays hundreds of stone skulls representing the victims of human sacrifice.

Gilded heaven for philatelists and architecture freaks, still in full working order despite sitting atop tremulous ground.

The only castle in North America to ever house European sovereigns.

Visiting this cacophonous collection of vintage novelties is like stepping into the mind of a crazed toymaker.

66,000 pieces of art, donated by one of the world's richest men.

A jaw-dropping "megalibrary" that turns book-browsing into a geometric adventure.

Part bookstore, part café, and part forest.

Frida Kahlo's childhood home, now a museum of her life and works.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

A whimsical brother of the nearby Fallen Angel statue takes the falling part quite literally.

Commonly acknowledged as the only public monument to the Devil himself.

A lush indoor jungle fills this bustling Madrid transportation hub.

An ancient Egyptian temple in the middle of Madrid, Spain.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.