Hanoi is located in the Red River Delta, in the center of North Vietnam. It is encompassed by Thai Nguyen Province to the north, Vinh Phuc and Ha Tay to the west and south, Bac Giang, Bac Ninh and Hung Yen provinces to the east and south-east. 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.