Brass bricks outline the locations of Edinburgh's lost, lively market stalls.

This extinct volcano rises above Edinburgh and is special for its panoramic views over the city.

A roadway designed for a visiting monarch.

An artist's whimsical transformation of everyday objects.

This sculpture of disembodied body parts forms a poignant memory of the horrors of World War II.

This striking art museum holds an amazing series of curiosity cabinets.

A place to eat for on-the-run agents and espionage enthusiasts.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

Home to items never before seen by the public.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

Look closely and you’ll notice that the color changes a third of the way up the tower.

The National Park Service’s best-kept secret with views that rival any in D.C.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

French prisoners carved these boats from the bones of their meat rations.

This museum is a music lover's introduction to the iconic venue.

A wall of chewing gum moonlights as collective art.

42nd story Pyramid shaped penthouse tops Seattle's oldest skyscraper.

Though strikingly beautiful, Seattle's other railway station is now largely forgotten.

The city's oldest Chinese restaurant offers local history and seriously good food.

The tech giant built three enormous glass orbs in Seattle so employees could work inside a rainforest greenhouse.