Tunick, who is known for his nude group photos in public spaces, posed participants for more than an hour in a variety of positions Monday.
"It was difficult to get the straight participants to embrace the gay participants and vice versa," Tunick said. "So I was very happy that that last set up finally got done and everyone came together (in a) united, friendly kiss, a loving kiss in front of this great structure."
Nineteen-year-old student Art Rush said he was thrilled to participate.
"I'll never get a chance to do this again, it's not worth being inhibited," Rush said. "It doesn't feel sexual, it just feels tribal, a gathering of humanity."
Nude people lay down as they gather on the steps of the Sydney Opera House while they pose for a photo by Spencer Tunick of the U.S. , Monday, March 1, 2010. 5,200 people stripped off for the commissioned photo that is titled "Mardis Gras: The Base." AP Photo/Rick Rycroft)