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.
Ya'an, a prefecture-level city of Sichuan Province, is located at the western edge of Sichuan Basin and the eastern foot of Qionglai Mountain, with Chengdu, Ganzi to the east, Liangshan to the south and Aba to the north, 120km away from Chengdu; it belongs to the mountainous area on the western edge of Sichuan Basin, spanning the Sichuan Basin and the Qinghai-Tibet Plateau; the climate type is subtropical monsoon humid climate; the total area of the city is 15046 square kilometers, under the jurisdiction of 2 districts and 6 counties; the total population in 2017 is 1.5378 million. Ya'an is located at the intersection of Sichuan-Tibet and Sichuan-Yunnan Highway, 120 kilometers away from Chengdu. It is the transition zone between Sichuan Basin and Qinghai-Tibet Plateau, the transition zone between Han culture and national culture, and the transition zone between modern central city and primitive natural ecological area. it was the gateway and necessary road of the ancient southern Silk Road and was once the capital of Xikang Province. It is the history and culture of Sichuan Province.