Tsozong Gongba Monastery (also romanized as Tsodzong or Tsomum) is a small Tibetan Buddhism monastery in eastern Tibet, China. The monastery, founded in 1400, practices the Nyingma tradition. Tsozong Gongba is located on Tashi Island (Chinese: 扎西岛; pinyin: Zhāxī Dǎo) in the middle of Pagsum Lake in the Nyenchen Tanglha Mountains, part of Gongbo'gyamda County in Nyingchi Prefecture, Tibet Autonomous Region. Tsozong Gongba means "castle in the lake" in Tibetan. The monastery has four buildings situated around a small yard.