Built hundreds of years ago this downtown iron barrier once protected a much despised king.

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

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

A notorious punk house turned co-op.

The world's tallest bridge is also possibly the most elegant.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

This lovely little burbling creek is actually a deadly waterway that has dragged down everyone who ever set foot in it.

A gigantic sculpture garden is packed with innovative oddities.

An Airy Would-Be Solution to a Housing Shortage.

A small Portuguese cottage formed between boulders in the countryside.

This awesome Spanish castle is so fantastical it was actually used on Game of Thrones.

This is the house that spite built.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

One of America's first dinosaur parks gives a window into Depression-era paleontology.

Sculpture designed by Turkish artist and professor Mehmet Ali Uysal.

A wonderfully strange collection of 500+ stuffed frogs doing people things.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

The dramatic upward-curving roof is one of the most iconic examples of Googie architecture that still stands today.

The sun acts as a key that only fits this giant keyhole twice a year.

The final resting place of soldiers' loyal canine companions.

What else would you call a playground hidden in Alabama's oldest and largest cemetery?

The unedited photograph called "Bliss" has graced the screens of over a billion computers.

This 38-drawer structure claims the superlative title, but it isn't the world's only giant filing cabinet.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.