Tonghai County (通海县, Tōnghǎi Xiàn) is in the southeastern part of China's Yunnan Province. Administratively, it's part of Yuxi Prefecture-Level City.
Tonghai County occupies the fertile valley of Qilu Lake. Mountain ranges surround the valley from all directions, separating it from Jingchuan in the north, Huanning in the east, Jianshui in the south, and Eshan in the west.
The county seat, which does not seem to have a commonly used proper name of its own (other than the official designation "Xiushan Subdistrict" 秀山街道) is located south of the lake, at the border of the plain and the mountains, separated from the lake by a mile-wide strip of farmland. The lake is surrounded by dikes, for flood control. The dike on the southern shore of the lake (the one facing the town) has a pleasant promenade on it; it is connected with the city by numerous concrete roads.
Tonghai's ethnic composition must have been greatly influenced by the Mongol conquest in the 13th century. To this day, the county has a large Muslim (Hui) population; numerous Hui towns and villages can be recognized from far away, by the domes and minarets of their mosques. The county also has Yunnan's only Mongol ethnic township (Xingmeng).
Tonghai is served by the new standard-gauge Kunming-Hekou railway. Several trains a day in each direction stop at Tonghai Railway Station 📍, which is located a few kilometers west of the county seat, near the road to Hexi Town. Similarly to other stations along the Kunming-Hekou Railways, the ticket office at the Tonghai train station has a complicated schedule (basically, it's only open around the times when a train passes through). There is also a train ticket office downtown, with a more sensible schedule.
2nd-order administrative division
Primary administrative division