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

The ruins of an ancient temple to the Aztec wind god discovered in the middle of a metro station.

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.

God's Saharan sandbox of wrath.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

Crumbling necropolis set high above Fez.

A fortified city, home to a remaining population of five families

The other side is actually green.

One of the most spectacular canyons in the world.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

One of only two commuter aerial tramways in the United States.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Pilgrimage site for star-crossed lovers.

A little sculpture with a large wardrobe.

Meet the bronze beloved pet to a family of famous peeing statues.

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The most visited, and possibly most controversial, museum in Germany.