'People came to donate their unopened pay packets in run-up to the Pope's visit'
It has gone down in history as something almost too immense to comprehend - but the small details of the visit by Pope John Paul II emerge as the most interesting of all.
A new exhibition chronicling the visit has been opened by Archbishop Diarmuid Martin in the Phoenix Park Visitor Centre as part of the preparations for Pope Francis's visit at the end of the month.
Most absorbing of all, perhaps, is a 15-minute film featuring many of the people who put the 1979 visit together, with its insight into the great effort that was made by the workers who made up the backroom team.
Eithne Merrins, who was over the financing of the visit, recalled how people had come to her to donate entire unopened pay packets.
When she would ask them how much they wanted back, they would reply: "We will manage."
"People weren't narky with each other, we didn't have time to fall out," she said of the gargantuan effort put in to organise the event in a window of a mere 10 weeks.
For Matthew O'Donovan, the foreman of the engineering firm that had erected the papal cross, his abiding memory was how physically difficult it was to get the structure onto the site at Phoenix Park.
It had to be transported on a lorry at 4am through the streets of the capital, leaving the workshop at Inchicore and down the hill at Christchurch.
While for Cyril McIntyre, who worked with CIÉ's press relations, the event was all about the biggest mass movement of the population in Irish history.
"Practically every bus in the country was in use that Saturday," he recalled.
There was a great gale of laughter from guests at the exhibition as they heard that the Pope had breakfasted that day on sausages, bacon, black pudding and brown bread, followed by three cups of coffee.
And there were even greater guffaws as they learned that directly after he had departed, a flock of nuns had descended on the red carpet with garden shears to carve it up as mementoes.
Afterwards, Archbishop Diarmuid Martin shared his own memories of that time, confessing that the papal cross in Phoenix Park stands as a symbol of something he had missed.
At the time he was in the Vatican and he recalled watching Pope John Paul's visit on a pretty poor quality television and feeling immense pride that this was his city and his diocese that had pulled off this historic spectacle.
Only recently, he had trawled through the archives and realised for the first time that the first the Irish authorities had heard of the '79 visit was through himself.
"Probably through gossip really," he added.
He had been in Philadelphia at the Mass when the Pope had announced the visit.
The vicar of Paris had come up to him and said "our cardinal is very disappointed... but we're delighted".
"I understand that as this visit gets closer and closer," the archbishop quipped.
Reggie McDonald, head ranger at Phoenix Park, has clocked up two papal visits in his career.
Asked if there was any difference in the planning, he immediately pointed out the technological advances.
The night before the visit in 1979 saw the rangers out on site in the pitch-dark with their torches.
But his strongest memory is of the people.
"They were all good humoured, all patient. That's how it was that day," he said.