The busiest train station in Australia, Sydney's Central Station, will be "reimagined" with a hub of shops, restaurants, office space and housing constructed over the rail corridor, NSW Premier Dominic Perrottet says.
The project, which will span 10 to 15 years, has been likened to the "cultural hub" created in Barangaroo, and will also result in new parkland that will connect surrounding suburbs.
"This won't be transformed next week," Mr Perrottet said.
"But over years, what you will see here is a completely transformed civic space, which will be beautiful, which then derives culture and character."
It will include 850 new dwellings, 15 per cent of which will be allocated as affordable housing and another 15 per cent will be diverse housing types like build to rent and student dwellings.
The project will renew 24 hectares of government-owned land with 15 new buildings ranging in size from four to 34 storeys, extending the southern end of the CBD.
"This is the busiest train station in Australia," Mr Perrottet said.
"But we don't want people just to come through, we want to enliven it, revitalise it and set out a brighter future for the Sydney CBD."
The Premier referred to "architectural sins" of the past which are now being "fixed" and said the area had transformed over time, but not to the level it should have been.
"We want this not just to be a tourist attraction, but an attraction for people right across our city."
The state government first raised the idea back in 2013.
The rail corridor divided Surry Hills and Ultimo in 1874 and Infrastructure Minister Rob Stokes said the proposal would "heal" what has become as "scar" through the centre of the city.
"Over six hectares of new parkland will be realised as part of this vision," Mr Stokes said.
The project is open to community feedback until September 19.
The announcement comes days after construction began on software giant Atlassian's 39-storey tower on the edge of the area.
That project, which the government said would "anchor" the Tech Central precinct, is expected to be open in 2027.