Taxidermied animals galore, by appointment only.

This silent sentry in the crypt below a large Gothic cathedral is often knee-deep in water.

Man-made cave with enigmatic carvings, some say made by the Knights Templar themselves.

This tiny little pool is said to be home to a malicious mermaid named Jenny Greenteeth.

This ethereal, rainforest-like gorge is home to waterfalls, quaint bridges, and fairy folk.

St. Mary's Asylum was isolated and abandoned before being converted into a Bed and Breakfast.

This Gothic Revival castle used as a shooting location for "The Secret Garden" and other films.

This romantic, decaying 13th-century ruin on the edge of Sherwood Forest is reputedly one of England's most haunted places.

An abandoned tank sits in an empty London lot as a symbolic middle finger to local city planners.

Public access to clean drinking water was an instant hit among the masses.

Dictionary Johnson’s favorite feline.

Shakespeare, David Bowie, Dr. Who, the Saxons, Druids and Romans are all claimed to have all made their mark on these massive man made tunnels.

Abstract dinosaur models in London.

The anatomical-pathological collection of a man who changed surgery.

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

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

Banksy gives themself artistic license with this piece of London street art.