This Boeing KC-97 tanker is now a restaurant for aviation lovers.

This volcano rises like a giant anthill from the plains below, with a road spiraling up to the rim.

The video game-themed street art first popped up in the French city.

These 18th-century paintings of Warsaw were used to reconstruct the city after World War II.

A hidden three-foot-wide house separates these two regal churches.

Elaborate tile work in this railway station tells the story of Portugal.

Ancient catacombs form the foundation for this Rococo orgy of a church.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

The stunning interior of this Gothic church is covered in ornate gold details.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

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

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.

The world's most elegant power lines.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

Hidden behind a wall, Spanish nuns distribute their signature sweets on a revolving tray.

The world's largest wooden structure.

The final resting place of the great navigator, or maybe his brother.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

The little church's beautifully frescoed ceiling has earned it the nickname “the Sistine Chapel of Madrid.”

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

A lush indoor jungle fills this bustling Madrid transportation hub.

A whimsical brother of the nearby Fallen Angel statue takes the falling part quite literally.