A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

The hallucinogenic center of the ancient world.

Monasteries on rock pillars, once accessible only by frayed ropes.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

An old department store turned Nazi prison turned artist commune.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

Elevated freight railway turned wildly successful urban park.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

The prototype for all Nazi concentration camps.

Berlin's old airport.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

A fascinating insight into daily life in the Eastern Bloc.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

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

Diego Rivera hid various people and symbols in his first large-scale mural project.

A jewel of the Mexico city skyline now slowly crumbles after surviving an earthquake.

Get a privileged view over Mexico City's Historic Center from a terrace right in its heart.

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

Mexico City's largest market contains a Willy Wonka-esque wonderland.

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