Photos: The prison that held Mandela Nelson Mandela speaks outside his former prison cell during a press conference in 2003 on Robben Island, off the coast of Cape Town, South Africa. From the mid-1960s through 1991, the island served as a maximum-security prison, mostly housing offenders of political offenses. Mandela spent 18 of his 27 years in prison on Robben Island. From 1964 to 1982, Mandela was incarcerated at Robben Island Prison in the cell shown. In 1990, he was freed.