Following the overwhelming success of World Expo 88, which attracted more than 15 million visitors, the attention of the Queensland government turned to the future of the South Bank site.

As revealed in cabinet minutes from 1988, which can now be released after 30 years, tenders were called and a shortlist was assessed by cabinet without public consultation.

The preferred developer, River City 2000, wanted to cut a canal into the shorefront area at South Bank and use that material to create Endeavour Island on the southern side of the river.

The artificial island and surrounding areas would include some parkland and the island would be dominated by a 60-storey office tower, hotel, World Trade Centre with the option of a casino, and recognition of the site's tourism potential.

However, the idea was met with backlash by the public, which had fallen in love with South Bank.

Solicitor Anthony Marinac, who compiled an overview of the cabinet documents, said Queensland came close to not having South Bank.

"It's now just about impossible to imagine Brisbane without South Bank," he said.

"It came very close to being sold off to private developers and there would have been a negligible amount of public space."

Former premier Mike Ahern said the development was designed to not cost the state government any money.

"We'll be able to do a commercial development there and the commercial development will pay the loan back," he said.

"It was a dream, it was never going to happen."

Mr Ahern said it was decided to start afresh, write-off $150 million and create the South Bank Development Corporation, which turned the parklands into an event destination, with its theatres, libraries and open parks.

Also thirty years ago, a proposal for an international spaceport on Cape York emerged and a bid for Brisbane to host the 1996 Olympics was entertained, but only if Athens did not become a preselected candidate.

Mr Marinac said the spaceport proposal was serious but the feasibility studies showed there would be a surplus of capacity worldwide to expected satellite launches.

"There was never a problem with the idea of the location, it was just going to be whether there was going to be sufficient commercial launches to support it," he said.

The saga of the world's tallest building continued until the proposal was defeated, resulting in a Supreme Court Challenge to the Brisbane Town Plan.