An underground art park? Art Gallery of NSW’s inventive new exhibition arrives

• Mike Hewson will turn The Art Gallery of NSW’s unique Tank space into an all-ages playground with dozens of interactive sculptures.
• The Key’s Under The Mat uses thousands of rescued materials to piece together a playground that’s designed for community.
• The exhibition is free.

New Zealand-born, Sydney-based artist Mike Hewson is next in a long line of artists aching to take over The Art Gallery of NSW’s unique, subterranean Nelson Packer Tank space, turning the industrial bunker into a concrete jungle with a park, play space, construction site, and a communal area framed by sculptural works.

Mike Hewson: The Key’s Under The Mat opens on October 4, giving the artist his first solo presentation in an art museum—a platform to heighten his unique approach to what an all-ages playground looks like. Visitors are encouraged to meet, dwell, play, make, perform and explore while interacting with the park’s various features.

Hewson has spent the last 14 months constructing the park in his Sydney studio, pulling together thousands of salvaged objects and materials with the stated purpose of creating a “spirited act of reclamation and regeneration.”

“This is the first time the Tank will have been revealed in full light, and the materials I’m using respond directly to its amazing textures and colours,” said the artist.

“Everyone working on the project knows how special it is to spend time with all these beautiful materials and make them into a place for people. I hope visitors to the park feel like they’re discovering something that’s already theirs.”

Hewson likens the park’s various sculptures to seeds that will sprout a “sense of possibility” for anyone heading along to play in the underground park. Creating an inclusive, interactive environment is part of the conceit, and reason for the exhibition’s curious title.

“The key’s under the mat, make yourself at home,” says Hewson as he invites

The Nelson Packer Tank space should once again prove its worth to Sydney’s creative scene. Since opening in 2023, the repurposed WWII naval fuel tank has welcomed some extraordinary site-specific works, as well as avant-garde music performances from the likes of Solange and Andre 3000.

Yet this is the first time The Tank will have been revealed in full light. Hewson has worked specifically with the space’s textures and lighting to inform where everything will go, from palm trees placed at the entrance to dozens of useful sculptures and spaces. The entire scene has been described by Art Gallery of NSW’s head curator of international art, Justin Paton, as “a handmade utopia rich with surprises.”

What to expect from Mike Hewson

The centrepiece Road plate public barbecue transforms a massive steel road plate into a communal cooking space, complete with five public grills and an exhaust system fashioned from a repurposed grain bin. It’s perhaps the clearest expression of Hewson’s vision of the artist as host, literally bringing the capacity to cook and share meals into the gallery’s heart.

Equally ambitious are the park’s functioning wellness spaces. Site-shed sauna repurposes a 1980s ATCO shed into a fully operational sauna, complete with bespoke pews, stained glass, and travertine flooring salvaged from the Art Gallery itself. Meanwhile, Milk-vat steam tank transforms a disused steel vat from Port Fairy into a sculptural steam room.

For creative pursuits, Green sound box offers a fully equipped recording studio housed in a weathered shed, its walls insulated with repurposed materials including Hewson’s own paintings. Below it, Bobby’s container provides open-use exhibition space, launching with playground concept drawings by children.

The playground itself centres on figure-8 monkey bars threading through the Tank’s concrete columns, while Tiny wide slide stack challenges adventurous kids to climb a structure assembled from wooden pallets, sandstone fragments, and heritage steelwork to reach a pink slide.

Perhaps most ambitious is the raised floor itself—1800 square metres paved with an ever-changing pattern of reclaimed materials carrying local histories, from blistered Corrimal Coke Works bricks to colourful 1970s towels, creating what Hewson calls “a place where anyone can find their place.”

Mike Hewson: The Key’s Under The Mat

Where: Art Gallery of NSW, Sydney
When: From October 4, 2025
Price: Free

artgallery.nsw.gov.au