This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Erotic art covers the walls of the largest ancient pleasure palace.

A small poultry graveyard in the courtyard of a popular Key West watering hole.

A historic presidential getaway on the continental United States' southernmost island.

A building so large that it has its own weather.

This abandoned NASA launch site is now a memorial to a trio of astronauts who were killed there.

A monument celebrating the idea of reaching inaccessible places.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

This failed condo development was reborn as a street art hub.

This historic train station has been converted to a locomotive themed hotel.

A white oak with property rights.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

A man's home is his castle.

This lovely burial mound is actually a replica that was installed after archeologists excavated the original.

Georgia's highest point was given its strange name thanks to a simple translation error.

They call this long foot bridge a swinging bridge, but really it's the bouncing you have to watch out for.