This luxury shopping lane has been protected by its own tiny police force for over a century.

A relic of Victorian grandeur hides beneath a busy South London road.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

Hidden behind a wall for decades, this masonic lodge was only rediscovered during renovations.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

The television series' iconic giant foot was borrowed from this classical painting.

London's smallest police station is barely the size of a phone booth.

The final resting place to 300 Victorian-era pets hides inside the city park.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

One part local history, 99 parts gruesome haunted house.

The sixth of London's "Magnificent Seven" cemeteries, and a source of unlikely inspiration to Beatrix Potter.

Art Nouveau painter Alphonse Mucha spent 18 years creating these monumental paintings of Slavic history and mythology.

Thousands of well-dressed mummies below a monastery.

The last of Philadelphia's wood-paved streets is now a landmark of terrible engineering.

Century-old shop, specializing in Occult products.

One of Philadelphia's largest murals resides hidden under this bridge.

The oldest surviving presidential residence in the United States.

Dr Barnes' $25 billion private collection of art and arboretum.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

This macabre painting of a Shakespearean scene looks like something out of a nightmare.

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

This bewitching Babylonian goddess haunts a hallway of the British Museum.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

Children's hospital in London that operates on royalties received from Peter Pan, which J.M. Barrie signed over in 1929.