Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

This small memorial honors a ferocious feline and local hero.

This pink watchtower served as the seat of the Greek government after independence from the Turks.

Legend says this sacred tree was a gift from goddess Athena.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A small island with shimmering pink sands, home to loggerhead turtles and rare plants.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

An unassuming secret door once led to a legendary watering hole.

This overlooked street light once served as a KGB dead letter box.

In 2013, historians discovered a hidden room devoted to the art of making royals' hot chocolate.

One of the world's tallest, oldest, and most disgusting chocolate cascades.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

Museum in a swimming pool where the water still flows.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

An artist weaves "wooden quilts" with scraps salvaged from his Katrina-damaged home in Tremé.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

Great place to have a drink and a bite to eat in an atmosphere laden with New York's Bohemian past.