The National Stadium, also known as the Bird’s Nest, is an 80,000-capacity stadium in Beijing. The stadium was designed for use throughout the 2008 Summer Olympics and Paralympics. It was used again in the 2022 Winter Olympics and Paralympics. The Bird’s Nest sometimes has temporary large screens installed at the stands.

Located at the Olympic Green, the stadium cost US$428 million. The design was awarded to a submission from the Swiss architecture firm Herzog & de Meuron in April 2003 after a bidding process that included 13 final submissions. The design, which originated from the study of Chinese ceramics, implemented steel beams in order to hide supports for the retractable roof; giving the stadium the appearance of a bird’s nest.

Leading Chinese artist Ai Weiwei was the artistic consultant on the project. The retractable roof was later removed from the design after inspiring the stadium’s most recognizable aspect. The ground was broken on 24 December 2003 and the stadium officially opened on 28 June 2008. A shopping mall and a hotel are planned to be constructed to increase the use of the stadium, which has had trouble attracting events, football and otherwise, after the Olympics.

In an attempt to hide steel supports for the retractable roof, required in the bidding process, the team developed the “random-looking additional steel” to blend the supports into the rest of the stadium. Twenty-four trussed columns encase the inner bowl, each one weighing 1,000 tons. Despite the random appearance of the Stadium, each half is nearly symmetrical.

With the removal of the retractable roof, the building was lightened, which helped it stand up to seismic activity; however, the upper section of the roof was altered to protect fans from the weather.

The eastern and western stands of Beijing National Stadium are higher than the northern and southern stands, in order to improve sightlines. A 24-hour-per-day rainwater collector is located near the stadium; after water is purified, it is used throughout and around the stadium. Pipes placed under the playing surface gather heat in the winter to warm the stadium and disperse heat in the summer to cool the stadium. The stadium’s design originally called for a capacity of 100,000 people; however, 9,000 were removed during a simplification of the design. The new total of 91,000 was shaved further when 11,000 temporary seats were removed after the 2008 Olympics; bringing the stadium’s capacity to 80,000. The farthest seat is 140 meters from the center field. The temperature and airflow of every surface were optimized to increase ventilation.

The stadium was used for the opening and closing ceremonies of the 2022 Winter Olympics and 2022 Winter Paralympics. It is the only stadium to host both the Summer and Winter Olympics and Paralympics opening ceremonies.

According to Wikipedia