Longyuan Lake in Kazuo (Harqin Left Wing Mongolian Autonomous County) lies at the source of the main stream of the Daling River. Longyuan Lake, a 4A national tourist attraction, is known as “the West Lake in northern China”. Its natural scenery and the cityscape blend together in harmony. The Longyuan Lake Scenic Area is adjacent to the Nanshao Wetland Forest Park upstream and the No.1 Bend of the Daling River Grand Canyon Resort Area downstream. They form an ecotourism belt with clear water, green beaches, beautiful scenery, and convenient transportation links.

Around March every year, a large number of migratory birds, which migrate north along the Eurasian migratory route, rest at Longyuan Lake. Visitors can admire more than ten species of birds, including swans, egrets, grey-hooded warblers, white-fronted geese, cormorants, and grey herons in Longyuan Lake. The number can reach several thousand. They are of great value to the ecosystem, bird watching, scientific research and conservation.