Tong Tso (Tibetan: སྟོང་མཚོ, Wylie: stong mtsho) or Dong Co (Chinese: 洞错; pinyin: Dòng Cuò) is a plateau lake in Gêrzê County, Tibet Autonomous Region. The name of lake means "Desolate Lake" in Standard Tibetan. The lake has a total area of about 87.7 square kilometers. Lying at an elevation of 4,396 metres, it is dotted with two islands.

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  Map including Tong Tso (labeled as T'UNG-KO HU (TANGKA TSHO)) (ATC, 1972)
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  Map including Tong Tso (labeled as T'ung-ko Hu) (DMA, 1975)
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  Map including Tong Tso (labeled as DONG CO) (DMA, 1990)