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

The elaborate clockwork contraptions in this Scottish gallery create small worlds of whimsy and horror.

A petite castle folly in the English countryside.

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

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

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

Fantastically decorated underground chambers built in the 1760s.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

One of the world's largest collections of pathological specimens.

A historic arboretum and non-conformist, non-denominational park cemetery.

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

A historic London cemetery now serves as a nature park incorporating gravestones & memorial statues.

Repository for more than 22 million pickled specimens.

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

A collection dedicated to the treatment of disease, held in London's oldest hospital.

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

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

Three bridges straddle a stream, one stacked upon the other.

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

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

Dictionary Johnson’s favorite feline.

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

This hospital once pioneered the use of electroencephalograms, but fell into maltreatment, abuse, and eventual abandonment.