The concept art for the Grand Canyon Skywalk was stunning. But the real glass pathway, jutting 70-feet out over the cliff edge, 3/4 of a mile over the river bed, promises to be far more so. What does it take to bring a project of this magnitude to life? A million pounds of steel, and 90 tons of tempered glass, apparently. Here are some of the first shots of the walkway's construction, courtesy of the LA Times' feature on the structure.