An underground art park by Mike Hewson opens beneath the Art Gallery of NSW

New Zealand-born engineer-turned-artist Mike Hewson has opened 'The Key’s Under The Mat,' an interactive social sculpture inside the subterranean Nelson Packer Tank at the Art Gallery of New South Wales in Sydney. The free exhibition, running from October 4, 2025 through 2026, transforms a former WWII oil reservoir into an art park featuring dozens of usable sculptures—including a functioning sauna, steam room, laundromat, playground, and barbecue—all made from thousands of salvaged objects. Visitors are encouraged to dwell, play, create, and even do laundry, with the artist describing the work as a 'handmade utopia.'