pay homage at the shrine before leaving the island. In 1982, former inmate Indres Naidoo's book "Island in Chains" became the first published account of prison life on the island. The maximum security prison for political prisoners closed in 1991. The medium security prison for criminal prisoners was closed five years later. With the end of apartheid, the island has become a popular tourist destination. It is managed by Robben Island Museum (RIM); which operates the site as a living museum. In 1999, the island was declared a World Heritage Site for its importance to South Africa's political history and development of a democratic society. Every year, thousands of visitors take the ferry from the Victoria & Alfred Waterfront in Cape Town for tours of the island and its former prison. Many of the guides are former prisoners. All land on the island is owned by the nation of South Africa, with the exception of the island church. Administratively, Robben Island is a suburb of the City of Cape Town. It is open all year around, weather permitting. Access to the island Robben Island is accessible to visitors through tours that depart from Cape Town's waterfront. Tours depart three times a day and take about 3.5 hours, consisting of a ferry trip to and from the island, and a tour of the various historical sites on the island that form part of the Robben Island Museum. These include the island graveyard,the disused lime quarry, Robert Sobukwe's house, the Bluestone quarry, the army and navy bunkers, and the maximum security prison. Nelson Mandela's cell is shown. Maritime hazard Seagoing vessels must take great care navigating near Robben Island and nearby Whale Rock (it does not break the surface) as these pose a danger to shipping. A prevailing rough Atlantic swell surrounds the offshore reefs and the island's jagged coastline. Stricken vessels driven onto rocks are quickly broken up by the powerful surf. A total of 31 vessels are known to have been wrecked around the island. In 1990, a marine archaeology team from the University of Cape Town began Operation "Sea Eagle". It was an underwater survey that scanned of seabed around Robben Island. The task was made particularly difficult by the strong currents and high waves of these waters. The group found 24 vessels that had sunk around Robben Island. Most wrecks were found in waters less than deep. The