This weekend’s Super Bowl between the New England Patriots and the Seattle Seahawks is being played in Glendale, Arizona at the University of Phoenix Stadium. Home to the Arizona Cardinals of the NFL, University of Phoenix Stadium was constructed at a cost of $455 million and took 3 years to build.
The building itself contains enough concrete to build 900 miles of sidewalk, has enough seats to span 9 miles if all 63,500 were lined up in a row, and has a retractable roof. It also has one other unique feature that was the first of its kind in a construction project. Can you name that unique design and construction element?