Guards will be posted at Wellington's Botanic Garden after a Friday night party left a WW1 memorial sculpture damaged and litter and broken glass strewn around Remembrance Ridge.
Pieces of the memorial sculpture Victory Medal, by artist Helen Pollock, have been broken, Gardens manager David Sole said.
The sculpture of 36 pairs of feet on a rusted steel medal has had some of the toes broken, but Sole was unsure whether it was intentional, saying it could have happened if somebody had been "mucking around" on the sculpture.
There were signs up asking people not to climb onto the sculpture, he said.
Council staff were "disgusted and disappointed" at the mess left behind, which took two hours to clean up.
"It's clearly a sign that the people involved have no respect," Sole said. "This is supposed to be an area for peaceful reflection - not antisocial partying and vandalism."
Late-night parties have taken place in the area in past years during the warmer months - but council staff were upset at the level of rubbish left this weekend.
Sole said they would post security guards at the site until "party season" ended. He expected the guards to be posted for the next four to six weeks.
The sculpture, which has toured New Zealand museums, will be repaired before it leaves Wellington in mid-November to travel to its final destination in France.
The sculpture will be installed at the French town of Le Quesnoy, to commemorate New Zealand's liberation of the town.