The glowing blue Nymphaeum of Emperor Tiberius.

Italy's third-largest Roman arena gives a peek into the underground operations beneath the ancient spectacles.

Pompeii's less famous neighbor is still revealing her secrets.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

There has been an astronomical clock on this spot since the 14th century.

Hundreds of hidden passageways weave through the old quarters of Lyon.

This beautifully deceptive waterfall is something far different from what it appears to be.

A mysterious pillar in an ancient burial chamber is said to predict how long you have to live.

The stoutest tree in the world.

These sacred Mesoamerican ruins feature peculiar petroglyphs hidden in the stones.

One of the city's few vendors selling the Sierra Norte's ancestral beverage lies within a hidden farmers market.

This stunning and ethereal mural symbolizes the beauty, unity, and diversity of humankind.

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 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.

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

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

At a museum of everyday objects, it is the act of collecting that is really on display.

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

Once home to an aristocratic family and a workers' organization, this intricately tiled building now houses a chain restaurant.

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

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

This pre-Hispanic apartment complex also includes ancestral paintings that point to its military past.