Hanoi means “the hinterland between the rivers” (Ha: river, Noi: interior). Hanoi’s territory is washed by the Red River (the portion of the Red River embracing Hanoi is approximately 40km long) and its tributaries, but there are some other rivers flowing through the capital, including Duong, Cau, Ca Lo, Day, Nhue, Tich, To Lich and Kim Nguu.
Hanoi lies at the centre of the triangular basin of the Red River. 50 km from Hanoi to the North, lies the tourist site of Tam Dao, and at the same distance to the South-West is Ba Vi. In Hanoi region, the chain of Soc Son (Soc Mount).is a prolongation of the mountainous mass of Tam Dao, which culminates at a height of 308m. This chain has different appellations: Ma Mount, or Temple (Den) Mount (because there is a temple on the summit of the mountain, called Den Soc, at the place of which Giong Genius was deified, rising to the sky on his iron horse), or Ve Linh Mount. Soc Mount is situated in the commune of Phu Linh, Soc Son district. Besides, Hanoi has other hills and mountains rising above the flat ground: Sai Mount (Thuy Lam commune, Dong Anh district) Phuc Tuong Mount (Co Bi commune, Gia Lam district) and at the centre of Hanoi, above the area of the old Botanical Garden stands the Nung Mount, also called Long Do or Khan Mount, giving more picturesqueness to the configuration of Thang Long.