A downtown Auckland stadium could become the city's Sydney Opera House or Statue of Liberty - with a Kelly Tarlton's in its basement, say its backers.
More details of the vision for the stadium have emerged as the group behind it asks Auckland Council for urgent help to make it happen.
A group of businesses, the Auckland Waterfront Consortium, want the stadium built as part of a major development at Bledisloe Wharf.
Auckland Waterfront Consortium chair Dave Wigmore said the underwater aquarium attraction Kelly Tarlton's could move into the basement, which would be built into the seabed.
The stadium could contain a Māori cultural centre, a conference centre and stadium tours, he said.
The group has said the stadium would come at no cost to the rate and taxpayers.
But at Auckland Council meeting today said they would need help from the council and government.
They want them to test whether the stadium is feasible and said work should begin on that before the end of the year to keep momentum going.
The group's deputy chair, Mike Sage, said though the consortium had created the vision, there was much more work that was needed to decide whether it could happen.
"But I am confident this proposal will fly," he said.
Councillor Alf Filipaina asked how the group could say there was no cost to ratepayers when it wanted the council to carry out the feasibility study.
But Mr Sage said the eventual developer, selected through a contestable process, would repay any costs.
"These costs are a short term loan to the project," he said.
Mr Wigmore said the group had met with Regional Economic Development Minister Shane Jones and planned to meet with Sports Minister Grant Robertson.
The government had indicated the council should take the lead on the stadium but recognised it would be a project of national significance, he said.