Guards will patrol a Battle of the Somme sculpture in Wellington's Botanic Gardens after partygoers damaged the touring artwork and left it covered in rubbish and broken glass.
Wellington City Council staff spent two hours cleaning up the mess left behind after the Friday night party on Remembrance Ridge.
"We're pretty disgusted and disappointed - and it's clearly a sign that the people involved have no respect," Botanic Gardens manager David Sole said.
"This is supposed to be an area for peaceful reflection - not anti-social partying and vandalism."
The damaged Victory Medal scultpure, by Helen Pollock, has been touring New Zealand and was installed in the garden in September.
It is in Wellington until November.
Security guards will be posted to the area in the coming weeks, Mr Sole said.