The IBM Pavilion at the 1964-65 New York World's Fair covered 54,038 square feet (1.2 acres) in Flushing Meadow, N.Y.

Designed by Charles Eames and Eero Saarinen Associates, the pavilion created the effect of a covered garden, with all exhibits in the open beneath a grove of 45, 32-feet high, man-made steel trees.

The pavilion was divided into six sections: The "Information Machine," a 90-foot-high main theater with multiple screen projection; pentagon theaters, where puppet-like devices explained the workings of data processing systems; computer applications area; probability machine; scholar's walk; and a 4,500-square-foot administration building. (Source: IBM)

Shown viewing the model in one of the Image Gallery pictures are Dean R. McKay, IBM vice president, and Charles Eames, co-designer of the IBM pavilion. (Source, IBM press kit)

Here's an IBM full page advertisement, touting the exhibition.

See the POPULAR SCIENCE magazine article below in Additional Notes, click on the image and you can read it.