The $1-billion Metropolis development in Downtown Los Angeles passed a major milestone this morning, when its fourth and largest tower topped out at the corner of 8th and Francisco Streets.

The 56-story tower from Greenland USA ranks among the tallest residential buildings in Los Angeles, soaring to an architectural peak of 627 feet.  At completion in 2018, it will offer more than 730 condominiums atop 67,000 square feet of retail and restaurant space.

Representatives of Greenland USA described Metropolis as "the fastest build project in the history of Los Angeles," noting that it employed some 15,000 workers through the course of construction.

Plans for Metropolis date back three decades, when a six-acre parking lot flanking the Harbor Freeway was imagined as a self-contained office tower complex designed by the late architect Michael Graves.  Various iterations of the project came and went without breaking ground until 2014, when Greenland USA acquired the property and revived it as a residential and hotel complex.

A full buildout of the project includes more than 1,500 condominiums, a 350-key Hotel Indigo and more than 70,000 square feet of commercial space.