Phoenix (/ˈfiːnɪks/ FEE-niks; Navajo: Hoozdo; Spanish: Fénix or Fínix,[citation needed] Walapai: Banyà:nyuwá) is the capital and most populous city of the U.S. state
of Arizona, with 1,608,139 residents as of 2020. It is the fifth-most populous city in the United States, and the only U.S. state capital with a population of more than one million residents.
Phoenix is the anchor of the Phoenix metropolitan area, also known as the Valley of the Sun, which in turn is part of the Salt River Valley. The metropolitan area is the 11th largest by population in the United States, with approximately 4.85 million people as of 2020. Phoenix, the seat of Maricopa County, has the largest area of all cities in Arizona, with an area of 517.9 square miles (1,341 km2), and is also the 11th largest city by area in the United States. It is the largest metropolitan area, both by population and size, of the Arizona Sun Corridor megaregion.
Gaotai County, which belongs to Zhangye City, Gansu Province, is located in the middle of Hexi Corridor and the lower reaches of Heihe River. it has been known as "Hexi key, five counties throat" since ancient times. The terrain is high in the north and south and low in the middle, with the northern foot of the Qilian Mountains in the south, the Heli Mountain in the north, the oasis plain in the middle, and the Heihe River running through the county. The county has a total land area of 4346.61 square kilometers and has jurisdiction over 9 towns. By the end of 2017, Gaotai County had a total population of 158000. Gaotai County has a long history, Han Wudi Yuanding six years (111 years ago) set the table as a county, when the "Silk Road" must pass. In the first year of Xiankang in the Eastern Jin Dynasty (335 BC), Zhang Jun of Qianliang set up Jiankang County in Camel City. Qing Yongzheng three years (1725), and Gaotai, town Yi Shou Qianhu Gaotai County. There are ancient ruins of Camel City and Xu Sanwan City in the territory.