Hundreds of hidden passageways weave through the old quarters of Lyon.

This modern museum of Mediterranean culture is surrounded by a surreal concrete honeycomb.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

Tallest - but not most powerful - wind turbine in the world.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

The silly symbol for an underground protest group is now scattered around the city.

An architectural oddity of six stories, accessed by graceful ramps.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.

10,000 flowered plants bloom in the City of Roses.

1513 Turkish world map, full of European state secrets and snarky commentary.

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

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

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

A fountain standing as a testament to a doomed alliance.

With its peeling paint and faded sign, this theater-turned-recycling plant is a nostalgic relic of 1950s Americana.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

148 feet long and in the middle of a verdant forest.

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

This Memphis recording studio launched the careers of Jerry Lee Lewis, Johnny Cash, and Elvis Presley.

Walk the whole Mississippi River!

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.

This stretch of beach along California's central coast is a busy highway for the largest seal in the northern hemisphere.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.