A relic of Victorian grandeur hides beneath a busy South London road.

This historic, one-acre island is the only legal place to camp in the city of Richmond.

Made of giant chains and hung with shackles, this iron cross honors those unknowns who perished under American slavery.

This lovely little burbling creek is actually a deadly waterway that has dragged down everyone who ever set foot in it.

A strange rock with a sinister reputation lurks within the crimson waters of this Scottish glen.

Wedged between two buildings at the Great Ormond Street Hospital is this secret music installation.

A network of concealed passageways lies within a busy London Underground station.

Artists and musicians now rule over this former rail station.

Repository for more than 22 million pickled specimens.

Hear the quietest sound from across the dome.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

One of Europe's oldest libraries.

The Columbia Road Flower Market is now open every Sunday, rain or shine.

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

This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.

A toy store with a century-long history preserves the craftsmanship of playthings of the past.

Hidden behind a wall for decades, this masonic lodge was only rediscovered during renovations.

This small museum in a former church crypt contains artifacts of the Elephant Man, Jack the Ripper and Florence Nightingale.

A closed London rail station created to cart away the dead still bears the marks of attempts to make it less morbid.

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

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.