Ha Giang Province is a province in northeastern Vietnam. It is located in the far north of the country, and contains Vietnam's northernmost point. It shares a 270 km long border with Yunnan province of southern China, and thus is known as Vietnam's final frontier. The provincial capital, also called Ha Giang, is connected by Highway 2 and is 320 km away from Hanoi. The border crossing is at Thanh Thuy, 25 km from the capital, Ha Giang town. It is one of the poorest provinces of Vietnam as it has mountainous topography with the least potential for agricultural development. The province borders China with a length of over 270 kilometers (170 mi); the border gate is known as the Thanh Thuy. In addition, there are three smaller gates namely, the Pho Bang, the Xin Man and Sam Pun.