The old observatory in Copenhagen has a spiral corridor used as a racetrack.

The only surviving piece of Copenhagen's 16th-century defensive wall.

The last Viking king of Denmark is buried inside the crypt of this cathedral.

This risqué sculpture, based on a Hans Christian Andersen fairy tale, caused outrage 35 years after it was erected.

A medieval church with largest and oldest collection of Renaissance frescoes in France.

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

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

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

It's believed this golden brick is part of the legendary lost Aztec treasure.

The unique collection often goes unnoticed by visitors focused only on the archaeological objects.

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

The turquoise-studded skull of a long-dead Aztec man sits within Mexico City’s Museum of Anthropology.

The most complete statue of this Aztec god sits a top a throne carved with images of hallucinogenic plants.

This immense scene of a cosmic battle between a jaguar and serpent illustrates the Aztec concept of the duality of life.

This colossal ancient sculpture of the monstrous Aztec rain god has a literally stormy history.

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

This colossal ancient jaguar sculpture was used as a vessel for the hearts torn from sacrificial victims.

The striking jade death mask of an ancient Maya king is displayed in a replica tomb in Mexico City.

In Chapultepec Park there is a pavilion gifted to Mexico from South Korea to honor the 1968 Summer Olympics.

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

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

The patron of this extravagant Art Nouveau confection insisted that nothing less than a boat should project from its facade.

This legendary giant, born from vegetables, terrorized townspeople and cheated local children in games.

This former guildhall with a bacon-like exterior is now home to a museum covering 600 years of Antwerp's musical history.