Ba Be National Park is a reserve in Bac Kan Province, Northeast Vietnam, set up to protect a freshwater lake (Ba Be Lake) along with surrounding limestone and lowland evergreen forests. It is located about 240 kilometer northwest of the capital city Hanoi.

Ba Be National Park is located in Bac Kan Province, about 240 kilometers north of Hanoi, about 70 km northwest of the provincial capital Bac Kan, and about 14 km west of the town of Cho Ra.

Ba Be Lake (Vietnamese: Ho Ba Be, Ba Be meaning "Three Lakes" in the local Tay language) is the largest natural fresh water lake, stretching about 8 kilometers in the northsouth direction. The surface area of the lake fluctuates between 3 and 5 km² between dry and wet season. Unlike many lakes in Karst limestone areas, Ba Be Lake never falls dry. Its average depth varies between 17 and 23 meters, the maximum depth is 35 meters. The lake lies about 150 meters above sea level, making it also Vietnam's highest. The name "Three Lakes" refers to the three parts of the lake named Pe Leng, Pe Lu, and Pe Lam. All these three parts are connected into a single continuous body of water, however.

The Ta Han, Bo Lu, and Leng Rivers feed into the lake from the south and the west. During the dry season, water is drained from the lake northwards into the Nang River. During high floods in the wet season, the latter flow is reversed however, and the lake takes up water from the Nang River thereby acting as a buffer regulating flooding.