My suite at The Silo hotel in Cape Town came with an entrancing 180-degree view of the marina, the Victoria & Alfred Waterfront and a cobalt-blue expanse of the South Atlantic. Despite the opulence of its interior, with its chandeliers, velvet sofas, art deco-style furniture and original contemporary art, I often found myself heading outside to my small balcony, to revel in the gusts of sea air and to listen to the cries of the seagulls. There, my eye was frequently drawn to the horizon and specifically to a low-lying smudge of land.

The boat tour from the waterfront to Robben Island takes around three and a half hours, and it is so popular that advance reservations are recommended. Its highlight — if that is quite the appropriate word — is a visit to Nelson Mandela’s cramped cell, with its barred window, single lightbulb, tiny stool and bedroll on the floor. Prisoner No. 46664 spent 18 of his 27 years of imprisonment there, before becoming the first president of post-apartheid South Africa. In his autobiography, Mandela recalls his arrival and being greeted by the guards with shouts of “This is the island. Here you will die!” His principal activity for close to two decades was breaking rocks in the island’s limestone quarry.

Like Alcatraz, Robben Island had a splendid panoramic view of one of the world’s most beautiful and hedonistic cities, and part of the extreme nature of the punishment was being virtually within touching distance of all of life’s most conspicuous pleasures. “The city looked agonisingly close, as though one could almost reach out and grasp it,” Mandela wrote.