Because sometimes the most efficient route from A to B isn't a straight line.

A painfully obvious spy house sits right across the street from the Russian Embassy.

This study room in the New York Public Library saw the creation of one of contemporary America's greatest traitors.

A museum dedicated to secret surveillance.

If you visit the burial place of King Frederick the Great, you'll likely find a couple of potatoes sitting on his tombstone.

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

An inconspicuous footbridge beloved by San Diego locals.

A historic jail preserves etchings from over a century of incarcerated people in a town with a rough and tumble past.

A luxurious doomsday bunker hidden beneath an unassuming Las Vegas home offers the best of subterranean suburbia.

Steepest flood safety railway in the entire world.

A strenuous, unofficial trail leads to spectacular views in one of America's most remote national monuments.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

Everything in this two-story house—down to the mounted deer head on the wall—was carefully crafted from concrete.

Everything from alchemy books to building plans for the Eiffel Tower are housed inside this museum.

The site of the world's first modern seismometer.

Take a ride back in time with a steam locomotive trip through Eritrea’s mountainous countryside.

Scrap material from around Eritrea finds a new life at this outdoor market, where upcycling is a lifestyle.

This cannonball embedded in the side of an Edinburgh house once served a surprisingly pedestrian purpose.

Featuring Torres Strait Islander cuisine and Australia's first indigenous bar.

A modern mechanical planetary system, part of a 10,000 year clock.

A huge musical instrument played by the ocean.

Building owners can take out tiles for free at this repository for historic building materials.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

No passport is required to eat around the world at this elegant restaurant.