While you wait to cross the street at a traffic light in Mainz, you might notice that the light is staring back at you.

The final resting place of the famed German pilot, the "Red Baron."

This tremendous timepiece was once the largest cuckoo clock in the world.

This disused boat elevator was saved from the scrap heap so that visitors could tour its rusting skeleton.

The tomb of a hard traveling saint is constantly covered in shoes as offerings to heal disabled youth.

Miles of man-made caves and tunnels are currently used for cultivating mushrooms.

Ivy-covered Medieval tunnels cut through this charming town in France's Loire Valley.

A 2017 crowdfunding campaign saved this historic castle from being destroyed.

This narrow path was cut right into a French mountainside to feed the country's early naval expansion.

Designed in the Romanesque style, this structure was once a fortress monastery.

This army of concretions is an unexplained geological phenomenon unlike anything else in the world.

This historic stone gate tower is now just a lonely relic in the middle of a swamp.

700 iron sculptures crammed into a Mediterranean park.

This ancient theater was once the home of fierce gladiatorial battles.

A unique underground structure dating back to the 1st century BC.

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

Even France's favorite aquatic son Jacques Cousteau, couldn't get to the bottom of it.

These medieval ruins have survived since the 12th century, even providing shelter from the Nazis.

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

The people's champion of the French Revolution was so overcome by grief at his wife's death that he exhumed her in the dead of night to make one final replica of her face.

Located in the house where Gustave Flaubert was born, this odd museum has more to do with medical grotesquery than the Western novel.

A former milk-delivery driver and his wife turn their home into a glimmering mosaic.

The great Italian Renaissance painter was laid to rest here in the Chapel of Saint-Hubert.

A once drab public housing estate is transformed into a colorful gallery of trompe l’oeil murals.