Mayor Albert E. Cobo (1875–1957) supported the construction of this convention and exhibit hall on and near the site of the Cass Farm Subdivision. Here, on its completion in 1960, Detroit held its first National Automobile Show. Next to Cobo Hall, and connected to it by a three-level glass and steel link, is the circular, green granite–walled Cobo Arena, below which are glass-enclosed offices. An extensive exhibition area is available, and from the lower-level ballroom and cafeteria is a panoramic view of the Detroit River and Canada. The expansion and renovation of light gray granite and green-tinted glass doubled the center's size, making it one of the largest convention halls in the nation. The North American International Auto Show is held here annually. Modular cubes of the primary facade telescope inward to give focus to the glass-walled main Washington Boulevard entrance. The Cobo Hall Helix Ramp spirals up sixty feet to a precast-concrete bridge that carries automobile traffic to rooftop parking.