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

A verdant 17th-century-style garden hidden along Edinburgh’s Royal Mile.

Scotland's oldest purpose-built concert hall houses an incredible collection of ornate, centuries-old keyboards.

The 20th-century chapel’s intricate woodwork includes amazing details, most notably angels playing bagpipes.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

This magnificently macabre shield shows the power of chivalrous love in medieval times.

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

The monster at the center of the Darwin Center Spirit Collection.

A plaque marks the underground site of one of London's "lost rivers."

A living memorial to the trees London lost during the Great Storm of 1987.

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

The final resting place of a German diplomat's beloved companion.

The gigantic skull of a long-extinct species that once roamed the forests of England and Ireland.

These ornate arches show how the course of the River Thames has changed.

A traditional American farmhouse plopped in the middle of a Piccadilly courtyard.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

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

One of the greatest movie directors of all time lived and worked in this London flat from 1926 to 1939.

This intricately carved and hilariously huge bed was such a famous symbol both Shakespeare and Byron used it in their writing.

Colorful murals by Jean Cocteau hide within this peaceful London sanctuary.

A former hardware store near Yerba Buena is the official home of California's history.