The National Tennis Center (), is a tennis center located in the Olympic Green. It opened on 1 October 2007. It hosted the tennis preliminaries and finals of singles and doubles for men and women at the Beijing 2008 Olympics as well as the Paralympic wheelchair tennis competitions. In 2009, it became the home of China Open. General information The center is located in Beijing, just from the Beijing National Stadium (a.k.a. The Birds Nest Stadium). The tennis center covers an area of with a floor space of . The center currently has 12 competition hard courts and 35 training courts, including 20 hard courts, 10 indoor hard courts, 2 artificial grass courts, 2 indoor clay courts, and a mini hard court. The main court, named Diamond Court (nicknamed National Tennis Stadium), has a capacity of 15,000. The Lotus Court (10,000 capacity), Moon Court, and Brad Drewett Court all have 12 stands, which represent pedals of lotus flowers, one of the emblems of the 2008 Summer Olympics. Lotus court has a capacity of 10,000. Moon Court has a capacity of 4,000 and Brad Drewett Court has a capacity of 2,000. The courts have been specially designed for natural air ventilation to reduce the amount of air pollution entering the courts, ensuring optimal health for both athletes and spectators. It also allows the courts to be cooled and with an installation of cooling machines, the courts' temperatures can easily be reduced to five degrees Celsius. Curtains attached to the roofs of the courts also allows them to be cooled in the heat of the sun. The project embodies the concepts of Green Olympics, Hi-Tech Olympics, and People's Olympics. It integrates design experience of world sport architecture and will be a tennis competition venue of the state of the art design in keeping with international standards. In 2009 the China Open, which is an ATP World Tour 500 series event and a WTA Premier Mandatory tournament, moved its location to this center from its former location, the Beijing Tennis Center. Rename The National Tennis Center was named as The Olympic Green Tennis Center or Beijing Olympic Green Tennis Court (), at the Beijing 2008 Olympics. Since it started to host the China Open, the venue was renamed to National Tennis Center in 2009. Timeline Before The Olympics All courts except for the National Tennis Stadium were opened on 1 October 2007 and