Sixteen months have passed since 601W Companies acquired Chicago’s abandoned Old Main Post Office building from deceased British billionaire Bill Davies and announced plans to convert to hulking structure into 2.5 million square feet of new Class A office space. Since then, the New York-based commercial real estate giant has so far played things close to the vest regarding their exact plans for the sprawling riverfront structure. Though early renderings from project design architect Gensler provided a rough picture of some of the planned improvements, the precise look and scope of the renovation has remained largely a mystery.

Recent images appearing in a slide show prepared by brokerage firm Cushman & Wakefield as well as the online development forum Skyscraper Page seem to have shed light on aspects of the $300 million overhaul. These more far refined—albeit not necessarily finalized—renderings show the property’s restored Art Deco lobby plus new amenity spaces such as tenant lounges, retail offerings, a fitness center, and a landscaped riverwalk complete with food truck parking and a water taxi stop. While Gensler’s Chicago office did confirm ownership of the images, more changes are likely to come ahead of a formal announcement from 601W and its partners.

Considering its high-profile perch above the Eisenhower Expressway and its many years of vacancy and decay, it is little surprise that many Chicagoans have kept a close eye on construction activity at the Old Post Office. So far, permits were issued for a new roof, elevator system, stairs, plumbing, and over 2,400 fresh windows. A second, much brighter spotlight was recently shed on the renovation effort after it was announced that Chicago Mayor Rahm Emanuel was engaging Amazon CEO Jeff Bezos with hopes of luring the tech firm’s lucrative HQ2 second corporate headquarters to the Windy City.

With its prime riverfront locale, 18-foot ceilings, enormous floor plates, and pre-approved zoning for multiple adjacent skyscrapers, the Old Post Office is perhaps the most turn-key solution with ample room to expand should Amazon choose Chicago for its second North American base.

Though not naming the Post Office project specifically, Gensler Chicago managing principal Grant Uhlir offered us some insight about the evolving needs of a company like Amazon via email last week saying, “HQ projects of large complexity, scale, and magnitude of investment are best conceived and master planned to be developed in phases and realized over several years or more.”

“This approach is achievable, real, and provides flexibility for the company to pivot to business changes, economic cycles, and other outside industry drivers in an effective and meaningful way,” Uhlir added.

In addition to other cities vying for the prize, the Post Office will face fierce local competition from other Chicago sites such as Sterling Bay’s newly-revealed ‘Lincoln Yards’ campus along the Chicago River’s North Branch. Large-scale projects such as the redevelopment of the Tribune’s 30-acre riverfront Freedom Center, Related Midwest’s 62-acre vacant South Loop site, and the phased high-rise redevelopment of Chicago’s Union Station have also been mentioned as potential candidates.

With Amazon as a wild card, the official timeline for the Old Main Post Office renovation is still somewhat fluid. At this point, 601W and its partners have yet to make an official announcement. That being said, the building’s restored Art Deco lobby is expected to be the first space that comes online. It will likely be followed by retail and amenities components in order to bolster marketing efforts. If all goes to plan, tenants could potentially move in as early as January 2019.

The project has also launched its official website. While still quite sparse on new info and images, the site confirms that redevelopment will simply be dubbed “The Post Office” as opposed to some numerical name in reference to the historic building’s address or its year of construction.