Mutiplex have commenced main works at the $565 million Sapphire by the Gardens mixed-use development in the heart of the Melbourne CBD.

The announcement comes shortly after the completion of one of the largest concrete pours in the city's history, in which a 1000 square metre, area was covered over a day-long concrete raft pour. The three-metre-deep pour sets the foundation for the mixed-use precinct envisioned by Malaysian property developer S P Setia.

The site, which is in short walking distance of some of Melbourne's best theatres and restaurants, as well as Parliament train station, will house two-high rise towers upon completion.

The eastern tower, Sapphires by the Gardens, will feature 60 storeys and over 300 luxury residential apartments. The western tower will include 62 levels and is set to host Shangri-La, a new five-star hotel. The two will be united with a sky bridge at level 46, with the Sky Lounge within offering undisrupted views to the UNESCO world heritage listed Royal Exhibition Building and the surrounding Carlton Gardens.

"We are delighted to commence the main works on this world-class development which is set to be one of the most significant projects in Victoria," says Graham Cottam, regional managing director of Multiplex Victoria.

"As one of Multiplex’s largest projects currently underway in Australia, we are very pleased to secure this contract and look forward to working alongside S P Setia to develop this new inner-city landmark."

Excavation and piling commenced in March 2019, and work is scheduled to be completed in 2022.