Dong Dais one of the four original urban districts of Hanoi, the capital city of Vietnam. It is bordered by BaDinh to the north, Hoa n Kiem to the northeast, Hai Ba  Trung to the east, Thanh Xuan to the south, and Cau Gia¥y to the west. The district currently has 21 wards, covering atotal area of 9.95 square kilometers. It is the most populous district in Hanoi. As of 2017, there were 420900 people residing in the district.