It runs across three hectares of prime land in the parliamentary zone, is passed by hundreds of people a day and holds millions of dollars worth of art.
And the Sculpture Garden, between the National Gallery of Australia and the shores of Lake Burley Griffin, is now set to undergo a $60 million refurbishment.
In the grand Canberra tradition, the gallery has launched a major design competition to revitalise the lakefront garden, which was devised in the 1980s but never actually completed.
Today, it's home to around 65 sculptures, including Rodin nudes, a Japanese fog garden, a beloved series of bronze pears and an immersive Skyspace by James Turrell.
But there are also pockets of wasteland, a large, unwieldy staff carpark, serious accessibility issues and a lack of harmony with the rest of the gallery precinct.
Gallery director Nick Mitzevich said most people had no idea how big the garden actually was because so much of it was unused.
"One of the things that is important to note is the original garden was never completed," he said.
"And because we've added buildings, and car parks, there's a need now to tie it all together in a consistent way, that gives everyone of all mobility levels, the opportunity to be a part of the garden.
"You can't circumnavigate the gallery because the garden is reduced to pockets. We want to knit all of those issues together...we need more seating in the garden. We need better lighting, and we need technology that helps us host more events. And just the simplest things - we don't have enough toilet facilities, and at times shading for school groups.
"So all of those technical elements we could solve individually, but we wanted to make sure that they're all consistent and we have a long-term plan about how we might resolve those."
The gallery will announce the competition winner in October, to coincide with the addition of the most expensive artwork it has ever commissioned into the Sculpture Garden, Lindy Lee's $14 million Ouroboros, now under construction.
Work is then expected to begin in 2027.
The $60 million budget will cover construction only, and is being funded through philanthropic donations.
Prominent Canberra architect Annabelle Pegrum, who spent a decade at the helm of the National Capital Authority from 1998 to 2008, has helped guide the plans for the competition.
She said design competitions were part of a grand tradition in Canberra's history.
"It's really extending that incredibly rich legacy of design competitions to deliver significant works and places in the national capital, going back to the start with the designs for the capital itself," she said.
"The majority of the significant places and buildings in Canberra have all been procured by design competition."
These include the gallery itself, as well as the High Court, the National Portrait Gallery, Parliament House, the National Arboretum and the Australian War Memorial.
Dr Mitzevich said the gallery had decided to open up the design to all architects and landscape architects registered in Australia, for what will be a five-year project.
"This is a very, very important site, and opportunities to work on a cultural project in the Parliamentary Triangle in the capital are rare," he said.
"So because of the rarity, we think it's important that everyone has an opportunity to be involved.
"[And] there's complexity and dynamism in what we're seeking, so we don't want to predetermine the kind of teams that could be available because we think there is a great sense of innovation in the industry. And we want to encourage people to put together design teams that we haven't seen before."
Ms Pegrum said it was also a good time to revisit the National Capital Plan, which had always intended more integration between the gallery, the High Court and the Portrait Gallery next door.
And what many had long seen as problems with the site - the car park, the walkway, the dead spaces and the toilets - became exciting challenges.
"That's the sort of thing that designers relish, because that brings their full creative talent to bear," she said.
"Here it's about translating what is of cultural value, thinking through the original design intents, contributing to the intent of the National Capital Plan and this idea of place for the people, and for the first time really looking to stitch together the National Gallery landscape setting with the National Gallery building to create an art landscape.
"That is challenging, but extremely exciting."
The competition will be held in two phases: the jury will first assess the entries anonymously, with shortlisted entrants then invited to further develop their conceptual designs for progression to the second stage.
Dr Mitzevich said having an open anonymous first phase would ensure a level playing field.
"What we're trying to do is encourage dynamic teams to come together and we want to privilege ideas," he said.
The jury, chaired by architect and academic Philip Goad and including Dr Mitzevich, First Nations artist Nici Cumpston and renowned Chilean landscape architect Teresa Moller, is encouraging multidisciplinary partnerships from Australia, international or a combination of both.
Applicants are encouraged to include a landscape architect, an Australian First Nations practitioner, artist, architect and botanist or horticulturalist.
