The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

A 400-year-old church covered floor to ceiling in ex-voto offerings from the faithful.

One of the oldest masonic museums in Paris.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This crumbling, graffiti-covered mansion sits tantalizingly within reach of the proletariat who frequent a public park.

Hidden in a Scotland museum is a copse of extinct tree stumps.

The world's largest model of our planetary system.

The most visited, and possibly most controversial, museum in Germany.

A surviving remnant of the thick ice mass that once mantled most of Western Canada's mountains.

A huge musical instrument played by the ocean.

A series of five defunct panopticon prisons in Cuba.

The inspiration for the Patagonia Clothing logo, Cerro Fitz Roy turns pink at sunrise.

For a century, the tallest building in Tasmania was a tower built to manufacture ammunition.

Ruins of the Crusaders' headquarters.

The man who introduced reinforced concrete to the world demonstrated its genius by using it to build his own house.

Former hunting lodge of a duke who was an avid collector of impressionist works.

Perfume museum and library.