Thanh Hoa, city, northern Vietnam. It is situated immediately south of the Red River (Song Hong) delta region, about 85 miles (137 km) south of Hanoi, on a small tributary of the Ma River. Connected to Hanoi by road and railway, it is a growing commercial and industrial centre.
The Ma and Chu rivers, rising in Laos, flow eastward through the region to enter the Gulf of Tonkin. Agricultural and forestry products are abundant in the hinterland, and there are phosphate deposits. Besides industrial crops of cotton, tobacco, and peanuts (groundnuts), since 1976 specialized growing areas have produced sweet potatoes, jute, mulberries, rushes, and corn (maize). The government has adopted a policy of settling formerly nomadic ethnic groups there. A rail line connecting Hanoi with Ho Chi Minh City (formerly Saigon) runs north-south through the city. Historically, the area was the centre of the Le dynasty; tombs of the dynasty are at Lam Son, the centre of revolt against occupation by the Ming dynasty of China. Bronze-age artifacts have been found at Dong Son. Pop. (1999) 130,081; (2009) 147,559.