Scattered throughout London are ancient remnants of the city's former bounding wall.

Hear the quietest sound from across the dome.

One part local history, 99 parts gruesome haunted house.

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

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

Museum preserving torture methods from the past.

Two stone columns flank the grand Venice square, but there were supposed to be three.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Go inside to really appreciate this 500-year-old technological masterpiece.

This skeleton-filled altar piece served as a backdrop to one of the most iconic scenes in "The Sound of Music."

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

Every hour the doors open to reenact the legend of the heroic mayor who saved his town by drinking a gallon of wine.

This historic funicular system combines the old with the new while offering delightful views over the surrounding valley.

It's good luck to be mocked by this monkey.

Dress up like a miner and take a slide into the disco-lit depths of this once foundational salt mine.

The prototype for all Nazi concentration camps.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The fairy tale castle of the "fairy-tale king."

The embalmed remains of the communist leader lie within a custom crystal coffin.

The tiny statues form China's only known terracotta army from the Han dynasty.

The field of tiny caves that mark this Chinese cliffside are each their own historic Buddhist temple.

The once highest point in China blends symbolic design with a kick of adrenaline.