The Portuguese, British, and Dutch all used Robben Island as a place to put people they wanted out of sight. In 1658, Autshumato became its first political prisoner -- a Khoi leader accused of reclaiming livestock that European settlers had taken from his people. Later that century, people who resisted Dutch rule in the East Indies were shipped to Cape Town and locked up on the island. When the British took control of the Cape in 1795, they continued the tradition. By the mid-18th century, the island doubled as an asylum. In 1890, a leprosy colony was established there. The pattern held for centuries: whatever the Cape's rulers wanted removed from the mainland -- the politically inconvenient, the mentally ill, the physically sick -- they sent to Robben Island.

In 1936, the South African Defence Force took control, building new roads, a power station, and housing. The island briefly became a military installation, part of the coastal defenses during the Second World War. But from 1961, it returned to its oldest purpose. The apartheid government converted it into a prison for those who opposed the regime -- overwhelmingly Black political activists. Nelson Mandela arrived in 1964 and spent 18 years there. The prison's maximum security section held the leadership of South Africa's liberation movements: ANC members, PAC activists, trade unionists, student leaders. The medium security prison held criminal offenders. The political section closed in 1991 as apartheid began to collapse; the criminal section followed in 1996.

Robben Island's other residents have no interest in its political history. An African penguin colony, roughly 2,000 strong, has established itself on the island's shores. The waters around the island are treacherous -- several shipwrecks dot the coastline, including the Chanson de la Mer (1986) at Shelly Beach, the Han Cheng 2 and Sea Challenger (both 1998) in Rangatira Bay, and the Fung Thu (1977) on the southern shore. The strong currents and unpredictable weather that made the island effective as a prison -- escape was nearly impossible -- also made it dangerous for shipping. The lighthouse on Minto Hill has been warning vessels away since the 19th century.

Today, Robben Island is a museum and UNESCO World Heritage Site, accessible by ferry from the Nelson Mandela Gateway at the V&A Waterfront. The crossing takes about 30 minutes across Table Bay -- on rough days, it is a reminder of just how isolated the prisoners were. Visits are limited to 1,800 people per day, and during peak season the wait can stretch to two weeks. The tour lasts four to five hours, including ferry time. A bus circles the island, passing the lighthouse, the penguin colony, and the ruins of the leper colony. But the heart of the visit is the prison itself, where former political prisoners serve as guides. They walk visitors through the corridors, past the communal cells and the solitary confinement block, to the small cell where Mandela slept on a mat on the floor for nearly two decades. The guides speak from experience. Their testimony is the island's most powerful artifact.