What is the importance of Robben Island in the memoir, Long Walk to Freedom?

Robben Island is a maximum-security where Mandela is held as a political prisoner for 18 years in total. He is taken to Robben Island after the conclusion of the Rivonia Trial, in which he was given life imprisonment for sabotage against the government. Because so much of his life was spent there, Mandela spends two chapters on Robben Island, divided between the very differently titled subsections: “The Dark Years” and “Beginning to Hope.” In “The Dark Years,” Mandela outlines the grueling physical labor that he and the other prisoners were forced to do, such as carrying and shoveling stone in a nearby quarry. He is particularly critical of the warder’s harsh tactics of control, designed to dehumanize the prisoners and undermine any sense of collective solidarity that their situation might produce by giving the prisoners different diets depending upon their ethnic background. In “Beginning to Hope,” Mandela details some of the new liberties that he and the other prisoners were granted in the 1970s, such as limited opportunities to garden and exercise, better food, and eventually an end to the discriminatory diet system altogether.