Robben Island 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. It is of particular note that it was here that past President of South Africa and Nobel Laureate Nelson Mandela and past South African President Kgalema Motlanthe, alongside many other political prisoners, spent decades imprisoned during the apartheid era. Among those political prisoners was current South African President Jacob Zuma who was imprisoned there for ten years.