Robben Island (Afrikaans: Robbeneiland) is an island in Table Bay, 6.9 km west of the coast of Bloubergstrand, Cape Town, South Africa. The name is Dutch for "seal island". Robben Island is roughly oval in shape, 3.3 km long north-south, and 1.9 km wide, with an area of 5.07 km². It is flat and only a few metres above sea level, as a result of an ancient erosion event. The island is composed of Precambrian metamorphic rocks belonging to the Malmesbury Group.
Robben Island is internationally known for the fact that Nobel Laureate and former President of South Africa Nelson Mandela was imprisoned on Robben Island for 18 of the 27 years he served behind bars before the fall of apartheid. Kgalema Motlanthe, who also served as President of South Africa, spent 10 years on Robben Island as a political prisoner, as did the current President of South Africa Jacob Zuma.
Robben Island is both a South African National Heritage Site as well as a UNESCO World Heritage Site.