An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

Statue of death tucked in the University of Medicine courtyard.

An unusual number plate signifies the building's saucy past.

Weird wax anatomical models reside here, as do other anatomical specimens.

A surrealist timepiece by the artist of melting clocks.

A lone cannonball remains lodged in the walls of the Hotel de Sens as a sober reminder of a revolution.

France's national museum of scientific and industrial instruments.

Dedicated to the art of hunting, with juxtapositions of contemporary art.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

135 bronze medallions mark a French meridian line which once rivaled the hotshot Greenwich timeline.

The celebrated eyesore created by starry-eyed sweethearts.

In Florence's great Duomo, a 26 foot fresco honors a mercenary famous for attacking Florence.

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

A perfectly running 230-year-old silver automaton and music box.

Huge winged monument in the United Kingdom.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Natural history museum celebrating biodiversity with a parade of taxidermy animals.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.