This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

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

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.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This mundane post marks the old location of the city's main postal hub.

This obscure walkway links Edinburgh’s Old Town with one of the city's prime vantage points.

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

Overlooking the burial ground is a tower designed to prevent thieves from snatching the recently deceased.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

A 18th century graveyard and its astonishing cortege of macabre iconography.

This enormous, elaborate tomb looks oddly out of place next to a suburban Edinburgh bowling club.

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

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

Tiny effigies of the victims of Edinburgh's famous Anatomy Murders.

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

The world’s first museum dedicated to the history of childhood opened in Edinburgh in 1955.

This ordinary-looking mailbox has a rather explosive history.

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

The final resting place of soldiers' loyal canine companions.

The fountain marks the area where hundreds of accused witches were burned at the stake.

360° views of the city plus five floors of optical illusions and hands-on science.