In their imaginations, the two-tonne rock, which has pride of place in the playground, has become the final frontier, allowing them to explore strange new worlds, and seek out new life and civilisations.
The boulder also holds intrigue for the children because it was the boulder that fell off a St Kilda cliff face and smashed through the Roome family's house earlier this year.
For St Kilda Kindergarten teacher June Aerakis, the large rock was a dream come true.
''A few years ago, the back playground was redeveloped.
''I always said how lovely it would be if the kids had a rock to climb on, and everyone always said, `you're dreaming, there's no way we can get a rock in out the back'.''
It appeared the dream would be too expensive, she said.
''But when the Roomes' catastrophe happened, I asked if there was any chance of us having one of the rocks.
''Jennie [Roome] said no because they had all been taken.''
Mrs Aerakis said she had all but given up on the dream becoming reality before she retired at the end of this year.
The 67-year-old has been teaching for the Dunedin Kindergarten Association for 21 years - the past 10 with the St Kilda Kindergarten.
But little did she know the Roome family had organised a Fairfield Transport crane to remove the boulder from their house, and drop it into the kindergarten's playground earlier this week, much to the surprise and delight of Mrs Aerakis.
''It was a wonderful surprise. It's the best leaving gift.
''And the kids absolutely love it.''
Mrs Roome said it was nice to see the boulder in ''a more productive place''.
''I thought about turning it into a water feature in our back yard, but we're creating a lot more joy with it here.''
Mrs Aerakis agreed.
''There's going to be a lot of joy here for the children for years to come.''
