Children had a bouncy castle and there were stalls selling plants, produce and bone carvings. Others sold food and drink. Chop suey, fried bread, paua fritters, hangi and hotdogs were among the offerings.
Whanganui iwi spokesman Ken Mair was among the crowd, and talked about what Waitangi Day meant to him.
"Our tupuna, our ancestors, and the British at the time had a genuine belief to build upon positive relationships that would benefit each other. And albeit the benefits have been extremely one sided, with land confiscations etc, I remain very optimistic, after what's occurred in the last 30-odd years at least, that this relationship that they believed in will genuinely be as expected, on equal terms."
This year the celebration in Wanganui was paid for by the Pakaitore Trust, a body formed after Whanganui iwi were acknowledged as the owners of the Whanganui Courthouse and its site.
The trust receives rent from the Justice Ministry.
"We utilise that rent to advance the aspirations of our people, whether that be social, education, sport etc, and also to help support our river and land claims," Mr Mair said.
Others at the gardens were less sure about the occasion.
Indie Adam, 17, knew why Waitangi Day was celebrated, but not what it meant to her.
"It's a day off school," she said.
A group of Wanganui Collegiate students offered: "It's a day of celebration ... celebrating our Kiwiana ... coming together ... celebrating what we have now because of the treaty."
Some of the Wanganui Chronicle's readers also weighed in on Facebook about what Waitangi Day means to them.
Robyn Henare said marking the day was a way to "thank our past".
"To strive for fairness, equality and acceptance in all we do, embrace our family, friends and community, to eat, laugh and love. It's 'whanau day'."
Marion Eldby explained Waitangi Day in her household: "The flag's up, the roast thawing on the bench, pavlova in the oven. We're off to the river to celebrate with all the other whanau."
Tarsh Boniface said, "I like to call it New Zealand Day. We're heading off to Moutoa Gardens for some of the yummy food they have on offer."
Organiser Jay Rerekura said the day was much as it had been for the last few years, and people would be shoulder tapped in March and asked to help with next year's celebration.
"People have said we should've done this, and should've done that. It's good to have other people to bounce ideas off."