Yanjiao Town, which belongs to sanhe city, Langfang City, Hebei Province, is located in the west of sanhe city, bordering Dachang Hui Autonomous County in the east, southeast and south, Chaobai River and Tongzhou District in Beijing in the west, and Gaolou Town in the northwest and north, with an area of 108 square kilometers and a registered population of 35 1483 as of 20 18.
Chengde is a prefecture-level city under the jurisdiction of Hebei Province, an international tourist city of Hebei Province approved by the government of Hebei Province, and a regional central city connecting Beijing, Tianjin, Liaoning and Mongolia. The administrative area of the city is 395 1 1.89 square kilometers [5 1]. As of 20 19, the city has three districts and four counties, 1 county-level city and three autonomous counties. By the end of 2020, the permanent population of the city was 3,354,400 (the seventh census) [4 1]. In 20021year, Chengde achieved a regional GDP of169.7 billion yuan, an increase of 6. 1% over the previous year.