At first, it was only a small provincial prison. But between 1930 and 1945, thousands of Vietnamese patriots were imprisoned here. Key individuals who later became main leaders of the Revolution for National Liberation were incarcerated in the Son La Prison. In 1962, it was classified by the Ministry of Culture as one of the numerous revolutionary heritage sites in the Vietnam.

The penitentiary was partially rebuilt after 1952 bombings and visitors can visit the subterraneous tiny cells with food-serving hatches and leg irons. The museum also exhibits precious objects introducing the historical and cultural traditions of 12 ethnic groups living in Son La Province. Son La Provincial Museum welcomes tens of thousands of visitors every year.