Kwan Phayao is located in the Muang Phayao District of Phayao Province. It is the largest freshwater lake in Northern Thailand and the fourth largest in the country. The term "Kwan" in the local dialect means "pond" or "marsh." The lake was created by the Department of Fisheries, which built a dam to ensure that residents have access to water during the dry season. Furthermore, during the rainy season, the dam helps to control the flow of water, preventing it from flooding the farms and gardens located downstream.