Eyewitness: Spencer Tunick nude installation, SydneyPhotographs from the Guardian’s Eyewitness series Sydney, Australia: Some of the 5,200 people taking part in the nude installation by artist Spencer Tunick entitled Mardi Gras:The Base, pose on the front steps of the Sydney Opera House, 1 March 2010. Photograph: Greg Wood/AFP/Getty ImagesView image in fullscreen Sydney, Australia: Some of the 5,200 people taking part in the nude installation by artist Spencer Tunick entitled Mardi Gras:The Base, pose on the front steps of the Sydney Opera House, 1 March 2010. Photograph: Greg Wood/AFP/Getty ImagesExplore more on these topicsSpencer TunickEyewitnessInstallationPhotographyAsia PacificSydney