• Tucson
  • Haidian

Tucson (/ˈtuːsɒn, tuːˈsɒn/; Spanish: Tucson, O'odham: Cuk-Ṣon) is a city in and the county seat of Pima County, Arizona, United States, and is home to the University of Arizona. It is the second largest city in Arizona behind Phoenix, with a population of 542,629 in the 2020 United States census, while the population of the entire Tucson metropolitan statistical area (MSA) is 1,043,433. The Tucson MSA forms part of the larger Tucson-Nogales combined statistical area (CSA). Both Tucson and Phoenix anchor the Arizona Sun Corridor. The city is 108 miles (174 km) southeast of Phoenix and 60 mi (97 km) north of the U.S.–Mexico border. Tucson is the 34th largest city and the 53rd largest metropolitan area in the United States (2014).

Major incorporated suburbs of Tucson include Oro Valley and Marana northwest of the city, Sahuarita south of the city, and South Tucson in an enclave south of downtown. Communities in the vicinity of Tucson (some within or overlapping the city limits) include Casas Adobes, Catalina Foothills, Flowing Wells, Midvale Park, Tanque Verde, Tortolita, and Vail. Towns outside the Tucson metro area include Benson to the southeast, Catalina and Oracle to the north, and Green Valley to the south.

Tucson was founded as a military fort by the Spanish when Hugo O'Conor authorized the construction of Presidio San Agustín del Tucsón in 1775. It was included in the state of Sonora after Mexico gained independence from the Spanish Empire in 1821. In 1853, the United States acquired a 29,670 square miles (76,840 km2) region of present-day southern Arizona and southwestern New Mexico from Mexico under the Gadsden Purchase. Tucson served as the capital of the Arizona Territory from 1867 to 1877. Tucson was Arizona's largest city by population during the territorial period and early statehood, until it was surpassed by Phoenix by 1920. Nevertheless, population growth remained strong during the late 20th century. In 2017, Tucson was the first American city to be designated a "City of Gastronomy" by UNESCO.

Haidian District, which belongs to Beijing, is located in the west and northwest of Beijing, adjacent to Xicheng District and Chaoyang District in the east, Fengtai District in the south, Shijingshan District and Mentougou District in the west, and Changping District in the north. It covers an area of 431 square kilometers, with a boundary line of about 146.2 kilometers, 30 kilometers from north to south, and 29 kilometers from east to west, accounting for about 2.6 percent of the total area of Beijing. The area is between 39 °53 degrees north latitude and 40 degrees 09 degrees north latitude and 116 degrees 23 'east longitude. In the early Yuan Dynasty, the town of Haidian was near a shallow lake, so it was called "Haidian", that is, Haidian today. In September 1952, Haidian District was officially named, and the area under its jurisdiction was formed in January 1963. As of 2018, Haidian District has jurisdiction over 22 streets and 7 districts. As of
Airport In Haidian - Beijing Capital International Airport
Beijing Capital International Airport (Beijing Capital International Airport, IATA: PEK, ICAO: ZBAA), located in the northeast suburb of Beijing, China, 25 kilometers southwest of Beijing city center, 67 kilometers south of Beijing Daxing International Airport, is a 4F international airport   , is one of the three major portal complex hubs in China   , members of the international air cargo hub group in the Bohai Rim region   , the world's largest airport   .
Beijing Capital International Airport was built in 1958. On January 1, 1980, supporting projects such as the T1 terminal building, the apron, and the parking lot in front of the building were completed and officially put into use. On November 1, 1999, the T2 terminal was officially put into use, and at the same time, the T1 terminal was closed for renovation. On September 20, 2004, the T1 terminal was put into use again. In the spring of 2008, the airport expansion project (Terminal T3) was completed.  
As of July 2017, Beijing Capital International Airport has three terminal buildings with a total area of ​​1.41 million square meters; there are two 4F runways and one 4E runway   The length and width are 3800×60 meters, 3200×50 meters, 3800 meters×60 meters respectively; there are 314 seats in total; 252 domestic and foreign routes have been opened.    
From 1978 to 2018, the annual passenger throughput of Beijing Capital International Airport increased from 1.03 million to 101 million, ranking first in Asia and second in the world.   In 2019, the passenger throughput of Beijing Capital International Airport was 100.013 million passengers, a year-on-year decrease of 1.0%; the cargo and mail throughput was 1.9553 million tons, a year-on-year decrease of 5.7%; , No. 2, No. 1.  
In 2021, Capital Airport will add three new domestic destinations, namely Huai'an, Tumusuk and Jingzhou   .
Travel Sights In Haidian
Travel Notes In Haidian
Travel Asks In Haidian
Travel Asks In Haidian