During the discussions about what a National Science and Technology Centre in Canberra should look like, Professor Mike Gore gave this advice to architect Lawrence Nield: "let the children play" and see where that led them.
The result was a building that became known as Questacon and was about fun as much as innovation.
The spiral staircase allowed visitors to go up or down or in or out of the exhibits, and the glass foyer permitted passers-by to watch people discover the building.
Thursday marks 35 years since Questacon was opened, by Prime Minister Bob Hawke on November 23, 1988, as a joint Australian-Japanese Bicentennial Project.
There is a party, this Saturday and Sunday, and everyone is invited.
The free Community Celebration will be out the front of the building, along with half-price entry to go inside the centre.
"A family pass will be $35 for the 35th anniversary," Questacon director Jo White said.
The free outside activities will be held 9am to 5pm on Saturday and Sunday.
Questacon's Science Circus will guide visitors through 16 exhibits and science experiences. Our Excited Particles will perform Spectacular Science Shows on centre stage. And you will be able to meet a "Flightless Fairy".
Commemorative pins will also be handed out to the first 1000 visitors each day.
Questacon began in 1980 as a project of the Australian National University, in spare space at the Ainslie Public School, under the guidance of founder Professor Mike Gore.
In 1982, the Australian Bicentennial Authority proposed that a national science centre be established as a lasting memorial to the 1988 Australian Bicentenary.
The first sod was turned on the site in 1986 and the building was completed in 1988 at a cost of $19.64 million. The centre was built as a joint Australia-Japan Bicentennial Project, with the Japanese Government and business community contributing half the cost of the building.
Since the building opened in 1988, more than12 million visitors have been through it.
Ms White said Questacon was a "much-loved part of the community".
"It's brought science to so many people in an inspiring and engaging way," she said.
"It's also a must-do when people come to Canberra."
To celebrate the 35th anniversary, Questacon is sharing a collection of stories on the Questacon website.
The stories range from its history to the national impact of its touring programs.
Ms White said recent federal funding would be directed to extending the life of the building and specific upgrades including a revamp of the Mini-Q zone for babies to six-year-olds. It had also recently introduced a calm space for neurodiverse children.
She said there was also a lot of nostalgia around Questacon from young adults who remembered coming there as a child.
"We want everyone, no matter what their age, to help us celebrate 35 years of Questacon," she said.
