Dating back almost 400 years, the oldest public collection library in the United Kingdom was once the study hall of Karl Marx.

England's oldest surviving hedge maze has been confusing visitors for over 300 years.

A metal tree emits eerie, melodic notes on top of Lancashire's Crown Point.

The largest greenhouse in the world is home to over one million types of plants.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

Surreal riveted sea forts once protected the Kent shores from German attack.

An Oxford museum where visitors can have tea with the Mad Hatter and climb through the wardrobe to a fantasy land.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

The longest hedge maze in the world.

A student driver's nightmare.

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.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

Artists and musicians now rule over this former rail station.

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

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

A historic house left in "dramatic still life."

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

The world's oldest family-run magic shop is hidden beneath a bustling London thoroughfare.

There's an exclusive Beefeaters pub hidden in the Tower of London.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

A tongue-in-cheek arcade where the games are based on everyday life.

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