Single runway interrupted by a busy road that cuts across its middle.

The Cape of Good Hope is not quite as low as you can go on the African continent, but it's still geographically significant.

A South African bar inside a hollowed out 6,000-year-old Baobab.

This Frank Lloyd Wright summer house was designed along Lake Erie as a retreat for a client's wife.

A 19th-century architectural wonder designed by the "father of the skyscraper."

This unique crypt designed by Frank Lloyd Wright for his longtime friend was not completed in either man's lifetime.

One of Frank Lloyd Wright's greatest—and favorite—architectural masterpieces was almost lost.

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

A walk through the historic city center, under the streets of Seattle.

The U.S. Navy's last diesel-electric submarine rests half-submerged in the middle of Portland.

Still standing despite its considerable slant, this tilted lighthouse has become a local symbol of resilience.

This art shopping center still boasts pieces of its past as a textile factory.

Many people don't realize there’s a lot going on in—and below—the world’s tallest triumphal arch.

One of the largest wooden ships ever built is honored by a steel sculpture evoking her once-superlative scale.

This lovely, if imposing, piece of Canadian gothic is possibly the most photographed hotel in the world.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

The site of Paul Revere's historic two lantern warning.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

Scattered throughout London are ancient remnants of the city's former bounding wall.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

Hear the quietest sound from across the dome.

An unusual round church in London with a Templar past.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.