It was here on Robben Island, a Unesco world heritage site, that Nelson Mandela - and many of his comrades in the struggle - was sentenced to life imprisonment and served 18 years. Visiting the political prison, once a leper colony, and the former ANC leader's cell, is a pilgrimage that is particularly moving with a former inmate as guide. A minibus tour takes you to see the island's other points of interest, such as its quarries and penguin colonies.