Tuesday morning, workers will begin construction on one of the centerpieces of the Hudson Yards, a massive development that already has transformed the far West Side of Manhattan. NY1's Michael Scotto filed the following report.

What looks like a new city is rising on Manhattan's far west side. It's the largest private development in the history of the United States. 

"10 Hudson Yards, the Retail and 30 Hudson Yards," said Jay Cross, president of Related Hudson Yards.

NY1 took a tour of the $25 billion project.

It is far from complete, but it already has changed this once-deserted neighborhood. It will add 16 buildings to the skyline, new streets, parks and public spaces. 

In the middle is a 150-foot installation called the vessel, built in Italy and assembled here, starting Tuesday.

"It's sort of part sculpture, part exercise machine," Cross said.

Most of the 28-acre project is taking shape on a platform above an MTA rail yard. A time lapse video shows what workers have already done, decking over the eastern portion of the yard and then building on top of it. Next year, they will erect a platform over the western half of the site.

"We have the added complexity of not just building over the active rail yards, but the geometry to physically support our building through the rail yards," said Geoff Butler, structural engineer with Related Hudson Yards.

There are 5,000 construction workers here right now and 16 major cranes. In one of the buildings, they've used 100,000 tons of steel.  

The buildings that are now under construction include a huge food hall and upscale mall, residential buildings and a 90-floor office tower. Developers say they're not concerned about overbuilding or creating too many stores at a time when more and more people are shopping online. They say they're creating a dynamic new neighborhood that will be a magnet for visitors... especially from the enormously popular high line.

"There's so many reasons why people want to come here. That retail's the beneficiary but by no means the only reason," Cross said.

Most of the work on the east end of Hudson Yards is expected to wrap up next year. Then they will do it all again on the west side... hoping to complete that in 2025.