Colorado Springs is a home rule municipality in, and the county seat of, El Paso County, Colorado, United States. It is the largest city in El Paso County, with a population of 478,961 at the 2020 United States Census, a 15.02% increase since 2010. Colorado Springs is the second-most populous city and the most extensive city in the state of Colorado, and the 40th-most populous city in the United States. It is the principal city of the Colorado Springs metropolitan area and the second-most prominent city of the Front Range Urban Corridor. It is located in east-central Colorado, on Fountain Creek, 70 miles (113 km) south of Denver.
Lanzhou, referred to as "Lanzhou" or "Gao", or Jincheng in ancient times, is the capital of Gansu Province, an important industrial base and comprehensive transportation hub in northwest China approved by the State Council, one of the important central cities in the western region, and an important node city of the Silk Road Economic Belt. By 2018, the city had jurisdiction over five districts and three counties, with a total area of 13100 square kilometers, a built-up area of 321.75 square kilometers, a resident population of 3.7536 million, an urban population of 3.0415 million, and a urbanization rate of 81.03%. Lanzhou is located in northwest China and the central part of Gansu Province. It is located in the geometric center of the land territory of the Chinese mainland. It is a comprehensive transportation hub of railways, highways and aviation in Northwest China. It is also the headquarters of the army organs in the western theater of the Chinese people's Liberation Army. It is also the new Eurasian continental bridge.