Area: 4868.4 sq. km.
Population: 301.5 thousand habitants (2006).
Districts: Ba Be, Ngan Son, Cho Don, NaRi, Cho Moi, Bach Thong, Pac Nam.
Ethnic groups: Viet (Kinh), Tay, H'Mong, Dao...
Location: Lie in the middle of a vast limestone mountain range of Ba Be District, BacKanProvince, 240km from the north-west of Hanoi.
Characteristic: Being dubbed a "precious jade of Vietnam and one of 500 lakes recognised as worthy of attention.
Time: 10th day of the first lunar month.Place: Nam Mau Commune, Ba Be District, Bac Kan Province.Characteristics:Spring festival annual of the ethnic minorities usually arranged near Ba Be Lake, attracts many people.