Volunteer participants pose naked inside the Stadschouwburg theatre in Belgium during a photo session with Spencer Tunick in the northern Belgian city of Bruges. (Reuters/Peter Maenhoudt)

“Individuals en masse, without their clothing, grouped together, metamorphose into a new shape.” (– Spencer Tunick)

For 20 years now, New York-based photographer Spencer Tunick has been creating human art installations all over the world, calling together volunteers by the hundreds or thousands. He asks them to remove their clothes, in order to photograph them in massive groups. And they do.

His aim is an architecture of flesh where a great number of human bodies blends with the landscape, or juxtaposes with urban structures.

Warning:  Since the nudity is central to Tunick’s art, the following photos are not screened out all depict naked human bodies.

Naked volunteers pose for the US photographer Spencer Tunick on the largest glacier in the Alps, Aletsch glacier, in Switzerland, as…