Work is set to start on the first-ever rail tunnel under Sydney Harbour.
The New South Wales state government has awarded a 2.81 billion dollar contract for its construction to a consortium led by CIMIC Group, formerly known as Leighton Holdings, and engineering giant John Holland.
The twin-tunnel rail line will run for more than fifteen kilometres under the harbour and Sydney's Central Business District.
The tunnels will be completed by mid-2021, and form part of a 66-kilometre line that will link Sydney's north-west to its south-west via the Central Business District.
It's due to be operational by 2024.
New South Wales premier Gladys Berejiklian says it's part of a long-term plan for transport in Sydney being enacted by the state coalition government.