The Tudor-style cottage in the middle of the square is not quite what it seems.

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

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

Eighty million natural history specimens call this gargantuan museum home.

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

A mysterious shape catches the eye in this 16th-century painting.

The dance of this huge clock is a magnificent and eerie commentary on good and evil in the history of humankind.

A six-ton wedding present for the King of the Scots.

The colorful stairs are made with marble from the world's major quarries.

This early version of the guillotine was used to execute the man responsible for its construction.

Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.

Sprawled across the Great Hall ceiling are various constellations and images relating to the zodiac.

This king penguin is a knighted brigadier of the Norwegian Army.

The most loyal of little dogs, or a Victorian era publicity stunt?

A succession of eerily contemplative iron figures lead from a Scottish museum to the sea.

Protecting the dead from opportunistic body snatchers.

A statue in the heart of Edinburgh honors a bear that served in the Polish military during World War II.

A sweet symbol marks the place where torturous executions were once carried out.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

A book bound in the skin of an infamous criminal, along with countless other specimens.

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

Makers and sellers of the original and finest York Ghosts.

The last four extravagant street signs of London's historic banking street.

This one has sailed five times as far as Sir Francis Drake's famous ship.