A misnamed well, with a deep dark past.

A Red Cross memorial museum at the site of the Niš concentration camp that operated for four eventful years during World War II.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

A Serbian church lit by chandeliers made of weapons.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

Structure built from the skulls of vanquished foes.

A public work of art that also provides some relief from the summer heat.

A whimsical bridge adorned with decorative dragons.

This abandoned Slovenian military barracks has become a punky-political art squat.

This one-time health resort was used by aristocrats around the world.

Ancient serpentine sacrifice holder that has stood the test of time.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

Legend says if you stick your thumb in the hole and it gets wet, your wish will be granted.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

Founded as a refugee camp, now a popular tourist spot.

Art Deco stylings conceal the true nature of this bridge.

The last of a gourmet supermarket chain, this store helped spark California's Food Revolution.

This 15-story mural celebrates the 50th anniversary of the musician's iconic "At Folsom Prison" album.

I Street Bridge is the heaviest swinging center bridge in the United States.

At this 1940s-era neighborhood favorite, you can still drink a cherry phosphate.

Before it was abandoned and left to rust alongside the road, this riverboat starred in a John Wayne movie.