The celebrated eyesore created by starry-eyed sweethearts.

An atmospheric, medieval-themed book store hides in a 13th-century underground space.

A unique zoological park home to over 30 species of wild cats, both big and small.

This miniature Paris, built out of trash, is one man's two decade labor of love.

Guests can stay at a hotel in the former French abbey where lie the tombs of King Henry II and King Richard the Lionheart.

The mummified heart of Louis XVII, the lost dauphin of the French Revolution.

Natural mummies hidden in the crypt of a medieval French church.

His "Lionheart" is entombed separately from the rest of his body.

Perfume museum and library.

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

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

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

A centuries-old complex of hand-dug stone chambers has sheltered locals in times of trouble.

This medieval tower is all that remains of the castle where Joan of Arc was held before being burned at the stake.

A medieval church with largest and oldest collection of Renaissance frescoes in France.

Since ancient times these picturesque springs have been providing bathers with healing waters.

The Sun King's military models, saved from the Louvre.

A French valley with forests so lush it was nicknamed "the Small Amazonia of the Pyrenees."

There has been an astronomical clock on this spot since the 14th century.

A museum which takes visitors to the côté obscure of Paris.

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

Museum in a swimming pool where the water still flows.

The world's largest reflecting pool is just two centimeters deep.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.