NRG Stadium - first NFL stadium with a retractable roof

NRG Stadium (originally Reliant Stadium), which opened in 2002, was the first National Football League stadium built with a retractable roof. It has a seating capacity of roughly 72,000 for football and has hosted major events including Super Bowl XXXVIII in 2004. The retractable roof design allowed the stadium to host both indoor and outdoor-style events in the Houston climate.