With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

Home to items never before seen by the public.

The site of the climactic scene from the classic horror film is now a historic landmark.

This home on a quiet suburban street is completely covered with vibrant mosaics.

The pioneer of psychoanalysis spent the final year of his life here, still seeing patients on that famous couch.

A naturally mummified 2,000-year-old man.

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

An small and easily overlooked archaeology museum chock full of Egyptian artifacts.

London's old-school healing garden.

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

A makeshift shrine to the late rock star is still kept up on the nondescript façade outside 1 Logan Place.

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

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

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

A planned settlement in Pennsylvania once housed the aristocratic refugees of the French Revolution.

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

A rock maze opens up to a panoramic viewpoint at an abandoned mine full of ghost stories.