"The crystals are hollow and glacial blue in color. As with glass, it is really light that makes the Polyvitro crystals come alive."   —Chihuly
   

Continuing on, pedestrians will approach the Crystal Towers, which mark the center of the bridge. The towers rise forty feet above the bridge deck and serve as beacons of light for the bridge and city. Illuminated from the landscape below, the forms glow at night. Chihuly made the 63 large crystals in each tower from Polyvitro, a polyurethane material developed to withstand the elements. He first used Polyvitro crystals in the Crystal Mountain, a sculpture created for the exhibition Chihuly in the Light of Jerusalem 2000. The Crystal Tower elements are raw, brutal forms, monumental and bold, that appear as if cut from mountain peaks or taken from frozen alpine lakes.