Human-made caves excavated to hide a secret society of wealthy pagans.

This luxury shopping lane has been protected by its own tiny police force for over a century.

The sixth of London's "Magnificent Seven" cemeteries, and a source of unlikely inspiration to Beatrix Potter.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

The world's largest collection of witchcraft regalia.

Hidden beneath the streets of London is a secret subway that only carried mail.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

A kaleidoscopic warehouse-maze of handmade neon signs.

Since 1887, this old-school shop has stacked its shelves with extraordinary coffees and teas.

The secret wartime bunker built on the platforms of an abandoned Tube station.

This overlooked street light once served as a KGB dead letter box.

Drink your espresso at a Victorian-era urinal in this underground-restroom-turned-coffee-bar.

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

This hidden rooftop garden in downtown London offers a quiet respite from a bustling city.

An exercise in radical design and social living that became the epicenter of Soviet spy networks in London.

This secluded walkway overlooks a magnificently wild London green space.

These ruins of Francis Bacon's once-magnificent manor are hidden in the English countryside.

Following the trail of an old metro line, this scenic path is haunted by a creepy spriggan statue.