A labyrinthine network of chambers with a storied past hides below Edinburgh's South Bridge.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

The taxidermied remains of a once-great parrot.

More than a million titles fill the labyrinthine shelves of this prestigious private library.

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

Tombstones and enigmatic inscriptions hide within a vault beneath a popular London arts venue.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

Pop culture has helped to keep this iconic British building from being destroyed.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

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

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

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

This hidden green space is the city's second largest conservatory.

Hear the quietest sound from across the dome.

An unusual round church in London with a Templar past.

Eighty million natural history specimens call this gargantuan museum home.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

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

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

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

Granite rocks that concentrate waves into powerful jets.

It's beautiful, it's haunted and its claim to fame is that it's the oldest existing stone arch bridge in Australia.