Thanh Hóa is the northernmost coastal province in the North Central Coast region of Central Vietnam. It borders Sơn La, Hòa Bình, and Ninh Bình to the north, Nghệ An to the south, the Laotian province of Houaphanh to the west with a boundary of over 192 kilometres (119 mi) long, and the South China Sea to the east.

Hòa Bình or Hoà Bình is a mountainous province of Vietnam, located in the nation's Northwest region. It borders Phú Thọ province and Sơn La province to the northwest, Hanoi to the northeast, Hà Nam province to the east, Ninh Bình province to the southeast and Thanh Hóa province to the south. The province covers an area of about 4,590 km2 (1,772 sq mi) and as of 2022 it had a population of 875,380 people. In 2020, the GDP per capita of the province was estimated to be $2625.