Dunedin's offering a look into the lives of some of the most-studied people in the world.
More than 1000 Dunedinites have been tracked from birth - with the results influencing public policy around the globe.
Their contribution is now being celebrated at an exhibition, back where it all began.
Stepping back in time to the lounges and living rooms of the past.
Slice of Life is a journey through the generations and a walk down memory lane for many visitors.
"It's, you know, 'oh we had a bedspread like that' and 'oh we had a lounge like that'. Yeah it's great, it's a wonderful wonderful exhibition," Dunedin resident Judy Stewart told Newshub.
The exhibition's been updated for its return to Dunedin where the world-renowned study began in the early 70s.
It's tracked the progress of more than 1000 people's lives from birth through to middle age.
"We're able to bring them back and put them through some of the most rigorous testing in the world. Which means the results we get are particularly meaningful," says Slice of Life exhibition curator Sean Hogan.
Researchers saw 94 percent of living study members at age 45 - an impressive commitment for the world's longest-running longitudinal study.
"Not every single study member is incredibly keen to come, but such a lot do," Hogan says.
"Others are hugely proud, because they recognise what the study has achieved and therefore what they've achieved."
Study results have influenced social policy, health policy, and criminal justice processes both here and overseas.
"Yeah, I think it's brilliant. Just to have a study that's recognised worldwide out of Dunedin is really good," Dunedin resident Robert Blacow says.
"Very proud, very proud," fellow Dunedin resident Margi O'Connell adds.
The show's taken over a former Smith's City store, making room for interactive exhibits, including some of the tests the study members have done.
"And I'm really looking forward to having lots of study members and their families come through. And enjoy what they've been part of creating," Hogan says.
There'll be more hands-on opportunities next month, as part of the International Science Festival.
This study of a lifetime set to continue to follow its willing volunteers well into old age.
