Ai Weiwei has unveiled Mushrooms, a 40-metre public artwork outside Sydney’s Museum of Contemporary Art, comprising 500 cast-iron combat helmets arranged on an elevated platform. The installation links the mushroom-like shape of the helmets with decay, death and life’s fragility, while urging viewers to confront the continuing reality of war and the importance of peace.

The work grew partly from Ai’s research for his 2017 documentary Human Flow, which involved travelling through 23 countries to examine the migrant crisis and the role of warfare in creating displacement. His interest intensified after Germany offered Ukraine 5,000 helmets at the beginning of Russia’s invasion, and after four visits to Ukrainian frontline soldiers last year; the sculpture also responds to its Sydney setting and view of the Opera House, which Ai sees as symbolising peaceful civic life.