About 1,700 men and women have appeared naked in Tyneside in the name of art.
Starting at a chilly 0400 BST, they posed at four locations in Newcastle and Gateshead, donning plastic white ponchos to cross the River Tyne.
New York photographer Spencer Tunick enlisted the volunteers for Naked City, his first large-scale UK installation.
It follows his nude photo shoots in New York, Barcelona, Belgium and Brazil. "There is a sensual element to it, but it's not a sexual experience," he said.
Gateshead's Baltic Centre said the work would show "the poetic whole resulting from individual bodies arranged in a sculptural way in an urban setting".
This would "challenge traditionally-held views on nudity and privacy as well as social and political issues surrounding art in the public sphere".
Volunteers from around the world - including Australia, Belgium and Peru - signed up, among them a vicar.
They had to dodge chips and kebab remnants dropped by the previous night's revellers as they made their way around a cordoned-off section of the Newcastle and Gateshead quaysides.
Designer Cally Daniels, 34, from Edinburgh, said the event had nothing to do with exhibitionism.
She said: "It was strange not to be self-conscious in that environment - normally I wouldn't even wear a skirt, I only wear trousers, so nobody even sees my legs."
University lecturer Fiona Jamieson, from Newcastle, added: "The photos are of nude people, but there is nothing sexual about it.
"It's about being completely natural, normal human beings, and everyone can be in the photos."
A documentary following the event - Naked City: Spencer Tunick in Newcastle Gateshead - will be broadcast on BBC Three at 2100 BST on Sunday.
Tunick, 38, carried out the world's largest nude photo shoot in Barcelona in June 2003, when 7,000 volunteers stripped for the camera.
In 1994 both he and a female model were arrested in New York when she posed nude on top of an eight-foot high replica Christmas tree in Manhattan's Rockerfeller Center.
Among those taking part in Newcastle were Tunick fans who follow him around the world.