The document summarizes the National Stadium in Beijing, China, nicknamed the "Bird's Nest". It has the following key details: - It has a 330m long and 220m wide steel frame with a 69m tall lattice roof supported by 24 massive 500-ton precast steel truss columns up to 224m tall. - The 360km of steel was used to construct the outer shell and roof, with the inner shell constructed of concrete. An ETFE membrane was installed between the steel for the roof. - The irregular lattice roof pattern follows geometric rules and is composed of intersecting horizontal and diagonal trusses that crisscross and cantilever to support the 320m by 297