These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.

A gruesome and mysterious ancient sculpture of a pagan deity from the Roman occupation of Celtic Britain.

This intriguing Bronze Age artifact spent centuries hidden within a Welsh faerie hill.

This magnificently macabre shield shows the power of chivalrous love in medieval times.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

This London marker celebrates the spot where the world-famous English band was founded.

A unique tribute to the millions of animals who served and died for the British military.

An eccentric Victorian aristocrat's enormous collection of medieval armor and weapons from around the world.

A commemorative plaque at the door pays tribute to an "American Patriot" known for his betrayal.

The rose garden in Regent's Park where Pongo and Perdita met for the first time in Disney's "101 Dalmatians."

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

A beautiful Victorian statue shows France's enduring love of the rhinoceros.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

The celebrated eyesore created by starry-eyed sweethearts.

This bridge was constructed from the rubble of the infamous Bastille.

This emotive sculpture was originally created for the 1878 World's Fair.

Hear the quietest sound from across the dome.

An immersive projection art installation uses sound, scale, and light to take visitors inside classic works of art.

"In the Dark" Restaurant in Paris offers dinner in complete darkness.

The oldest stone house in Paris was built by its most famous alchemist.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.