Sangiin Dalai Lake (Mongolian: Сангийн далай нуур) is a salt water lake in northern Mongolia, located at the border between the Tsagaan-Uul, Shine-Ider, and Bürentogtokh sums of Khövsgöl aimag, and the Ikh-Uul sum of Zavkhan aimag. It is surrounded by mountains, hills, and rocks. The 8.4 M_w  Bolnai earthquake occurred nearby on July 23, 1905.