This ancient village and its adjoining cemetery have a beautiful history of death and remembrance.

A series of five defunct panopticon prisons in Cuba.

An architect transformed this abandoned cement factory into his castle-like workshop.

One of the world's few mounted blue whales, its jaws are hinged open allowing visitors to descend into a lounge.

A French valley with forests so lush it was nicknamed "the Small Amazonia of the Pyrenees."

Beneath the city of Lourdes, France is a massive, concrete church.

Strange masks and obscure costumes are housed in this old Madrid corrala.

This Spanish shoe museum has history, has design, and has a pair of Rafael Nadal's tennies!

This enchanting green space houses a labyrinth lined with toxic plants.

Hundreds of caves once used to store grains and animal feed.

The lengthy skeleton of one of the tallest Spaniards of all time is on display in Madrid.

Rare karst landscape eroded from a flat seabed.

This magical space partly designed by Antoni Gaudi is one of the best examples of romantic gardening in the Mediterranean.

Of course Salvador Dalí lived in a castle...

First planned industrial community in the United States.

A monument to the art of slicing people open.

A speakeasy takes on Chicago's drinking culture.

Narrowest house in Boston.

19th-century operating theatre in which the use of ether was first demonstrated - plus, a skeleton and a mummy!

A morbid secret lies hidden within the beautiful walls of the Boston Athenaeum.

An antique curios dealer and hybrid taxidermist.

The largest medical and anatomical collection in France lies hidden from the public.

Stripes of human ashes cover a back lawn in the most sought-after burial grounds in Paris.

A mud statue stands in the dark tunnels, seeming to hold up the weight of the city above.