Хуапхан
Houaphanh Province covers an area of . The province is bordered by Vietnam to the north, east, and southeast, Xiangkhouang Province to the south and southwest, and Luang Prabang Province to the west. The terrain is rugged, with dense, forested mountains forming much of the province, particularly on the western side. The main road running through the province is Route 6. The principal rivers are the Nam Ma, which flows from and into Vietnam, passing the village of Ban Muang-Et, and the Nam Sam, on which the towns of Sam Neua and Sam Tai lie.