Built as the centerpiece of the city's Hemis-Fair'68 exposition, the tower, built of slip-formed reinforced concrete, is the tallest structure in the city at 622 feet. Atop the shaft are six levels of observation decks and a restaurant that rotate once an hour. The tower is a collaborative effort between Boone Powell and noted Mexican architect-engineer Félix Candela, and is a precursor to numerous similar civic monuments from Toronto, Canada, to Seattle, Washington.