Initally designed just before Marina City, Astor Tower started construction in 1960 and was built practically at the same time. The plan is organized around a central core, which housed the elevators, stairs and utilities, thus allowing use of the entire floor plate for living space. There were four units per floors, with 96 units in total.
Goldberg exposed the core at the base of the building and again at top, highlighting its important structural role by making it a central feature of his design. Because the residential stories do not begin until the fifth story, the exposed core gives the impression of an architectural peep-show, the building lifting its exterior wall to expose its structure beneath. Poured in place over a three-week period, the core was slip formed, carried much of the weight of the building and resisted 90% of the wind stress this close to Lake Michigan. All twenty-four floors were cantilevered off the core, supported by perimeter columns as well. The detail of the corner columns, barely engaging the floor plan, is notable.
One of the most unusual feature of the building was the complex exterior adjustable louver system designed by Goldberg to allow light control, weather protection, and easier window washing. In addition to their functional capacities, they also create what Goldberg described as "a happening." As he wrote in 1965, "the changing pattern of light and dark on a haphazard basis regulated by the tenant creates a constantly changing elevation. Astor Tower appears to be a slightly different building each time one looks at it." Sadly, the Louver system was removed in 1996 during a renovation project.
The construction of Astor Tower was also unusual: after construction of the core was underway, the lower levels were made with slabs cast on grade, then the floor below was dug out (with a very small bulldozer from the mining industry) to the next level, and repeated again. the perimeter foundation walls were columnar, drilled and then cast, chosen instead of conventional sheet piling to lessen impact on the neighborhood structures.
The three hundred foot tall structure originally was a hotel with a French theme. It featured ninety-six dwelling-units and Maxim's de Paris restaurant, a replica (and franchise) of the famous French restaurant in the basement. A promotional brochure declared, "here an international clientele is offered the intimate atmosphere and individual attention of a great residence. Privacy and perfection of service, hallmarks of the elite club are the signature of this Gold Coast rendezvous for the chic and celebrated."