Beijing has two airports, namely the Beijing Capital International Airport and the Beijing Nanyuan Airport. The former one is located in the northeast of Beijing, about 30 km from the downtown. The latter is situated in the south of Beijing, about 13 kilometers from the downtown. There are 3 terminals in the Beijing Capital International Airport. The flights of all airlines take off and land here. Nanyuan Airport is a military airport and open to civil aviation. It is the main operating base of China United Airlines, and its number of flights is much less than that of the Beijing Capital International Airport. It is very convenient to travel to and fro downtown from the two airports. One can either take the shuttle bus or hail a taxi at the airport.