The tour guide who gave it the full Nelson

It was quite depressing, here in Cape Town, to discover the only way to see Nelson Mandela's old residence, the prison at Robben Island, was on the "official all-included tour". Surely they can't have turned the battle against apartheid into a Tower of London-style tourist attraction already, selling "township uprising" teddy bears and Nelson Mandela shortbread and one of those snowstorm things, except you tip it upside-down and see the effect of Mandela slopping out his bucket.

Official tours are hideous, especially outside Europe, where the guide usually kicks it off with a warning such as "whatever you do, make sure you're never more than 10 yards from the rest of the party, as the locals will hang you in their market and slowly bleed you to death". Then they whisk you past an extraordinary sight, with a sentence like "The building to your left is a 1,000-year-old octagonal mosque made from crab shells", delivered with the intonation of a tannoy announcement about evaporated milk at the Co-Op.

Or there's the jokes. "Up ahead you can see the remains of the cathedral that collapsed into the canal in 1826, bringing a whole new meaning to the phrase 'I'm just going to drop in on somebody'." And facts you know can't be right. "Over 20 thousand tonnes of soil was removed to make way for the canal, which is roughly equivalent to the weight of Italy."

So what would they do to Robben Island? Would we be told that "Nelson Mandela may have spent 27 years in jail, but he shared the island with over 40 varieties of wild bird, ranging from the chaffinch to the cormorants you can see on the rocks to your right"?

There was no other way to go, so I joined the group that boarded the catamaran for the island. And away we all went, stinking of suntan lotion and trying to avoid those tubby 70-year-old American couples that wear shorts and long white socks, just as if we were on an excursion round the bay at Monte Carlo.

Then we shuffled into the prison and the official guide gave us his opening line. "I know this prison well, because I was sentenced to 18 years here for blowing up a building of the South African defence corps intelligence unit." Now that's how to start an official tour. You don't get that at Hampton Court.

Then he told us about the apartheid system in the prison, which allocated bread rations according to race, and the hunger strikes that opposed this. He informed us how he passed a degree, but the prison authorities twice "lost" his exam paper, until a lawyer personally delivered his third attempt directly. It would have served the authorities right if his first two exam papers had been full of wrong answers and they had accidentally done him a favour. He related how his friend Johnson refused to fill in a hole after spending the morning digging it, so was buried up to his neck under the hot sun for the rest of the day. A guard told him "I bet you're thirsty, kaffir, here's some whiskey" and urinated on his head. He told us of the ceaseless political discussions and the smuggling of documents. And how he was called to the office to be told his father had been shot eight times by the army and sent back to work. The three men responsible, he said, were pardoned by the Truth and Reconciliation Committee and are now successful businessmen, while his father is blind and paralysed. Then he said "Any questions?"

What question are you supposed to ask after that? Would it be appropriate to say: "Was he shot with a regular .22 Magnum or the 9mm Luger, because those things are awesome?"

Perhaps the most moving aspect of this account was how the room filled with an eerie atmosphere, of a group of random and disparate people with watery eyes, while stood on sunburned legs and wearing baseball caps and T-shirts with slogans such as "I've been canoeing in Acapulco".

Just one English woman let the side down, saying after the shooting story" "Thank you. That was interesting." Interesting? I think she sort of missed the point. I suppose if she visited a torture victim, she'd say: "Thanks so much for a splendid evening. The coffee was delightful and the story of the electrodes certainly provides food for thought."

This isn't just a story of the past. Every wing of the British and American establishments is stuffed with people who spared no effort to protect the apartheid regime. Many of them have suddenly acquired a new humanitarianism, which they're keen to display by bombing Iraq, whereas our guide found it hilarious that Blair was embarrassed when Mandela called him "Bush's Foreign Secretary".

The other lesson is the opportunities in using celebrity prisons as a tourist attraction. Imagine the potential for guided tours to see Jeffrey Archer's cell, the only difference being it would only be an attraction while Archer was still in it.