Waitaki Community Gardens chairwoman Gloria Hurst was gardening with Papakaio School pupils when one of the boys found a metal box with a glass bottle inside that carried a map with a note on the back.
And the note had a message from ''150 years ago'', she explained with a wink.
It inspired the children to plant a time capsule in the garden as a part of the celebrations - and also resonated with the school's theme of ''kindness''.
Written on the back of the map the children found were the words of ''Sami The Wizard, Papakaio Gully, 1867''.
''Play in nature, 'tis contagious and free, nature is for everyone, and kindness is key,'' the message for the children reads.
An ''X'' on the map led the children to a collapsed cave on the nearby property of Mrs Hurst, who was also on the jubilee's organising committee.
Pupil Lachie Wright (9) was digging in loose dirt near the school garden with his schoolmate when he made the find.
''I hit something,'' Lachie said.
At first he thought it was just a piece of scrap metal, but the children opened the box to find the bottle with the message in it.
The paper the map and writing were on ''was quite delicate''.
The clues left behind, by what Lachie thought was probably a ''nature wizard'', were not easy to figure out, he said.
The collapsed cave was probably where the wizard lived, he said.
Those at the jubilee added to the time capsule inspired by the find, and a cheque book, an iPhone, and other items that might not be in use 25 years from now, when the capsule was to be dug up, were buried after a short ceremony in the school garden.
Organising committee member Jessica Wright said on Friday about 100 people registered for the three-day celebrations.
Principal Gary Shirley said he was ''very proud'' of his school and its history.
''It's not just the buildings,'' he said.
''There's a heritage of the community as well.''
