Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

The "Prussian Versailles" that is as glorious today as when it was built.

This small exhibition displays equipment and artifacts once belonging to the feared Stasi secret police.

One of the most iconic neon ads of former East Germany.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

This gem from the industrial age helps visitors and residents alike traverse hilly Stockholm.

A bronze statue of the famed Prussian naturalist commemorates the year he spent in Mexico.

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

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.

The burial place of some of Mexico's most prominent residents is full of macabre stories and hidden masonic symbols.

This crumbling Art Deco movie palace in Mexico City has been abandoned for two decades.

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

Meant to be one of the most extravagant hotels in the world, now an eerie, abandoned architectural gem in Mexico City.

Diego Rivera's massive tiled fountain and failed infrastructure project.

Part bookstore, part café, and part forest.

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

This dockworkers' lunch joint has been left leaning by a century of storm floods.

This contentious squat has stood through fire, violence, and government intervention as a hotbed of leftist protest.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

Hamburgers are intensely proud of their tunnel beneath the river.

This cathedral hides a sculpted dog that determines your fate and an unexploded shell from World War II.

Thousands of well-dressed mummies below a monastery.