U.S. Bank Stadium, the future home of the Minnesota Vikings, is approximately two-thirds of the way through its construction, and is still on track to be ready when the purple kicks off their 2016 season. It's a groundbreaking venue in a lot of ways, another of which is detailed in USA Today.
A lot of the article is focused on the composition of the stadium itself. Sixty percent of the building will be composed of a substance called Ethylene-tetra-flouro-ethylene, or ETFE (which is a whole hell of a lot easier to spell). It's the clear substance that will allow light to come in much like glass would.