One of Jo'burg's few claims to fame - apart from its crime rate - is that it is the world's biggest city unattached to water. It does not adjoin the sea or a lake, and no river runs through it. So the handsome new Nelson Mandela bridge, completed in time for the great man's 85th birthday celebrations last month, overlooks railway tracks and the unlovely rear of the downtrodden central business district.
The bridge allows the well-off inhabitants of the northern and (slightly more modest) western suburbs to soar straight to the Newtown cultural precinct, where theatre, dance and smart restaurants await them. They can ignore the harsh and often fascinating detail of a city obsessed with weapons, hair, liquor and meat - Bree Street, for example, where in a variety of "butchery restaurants" you can eat a hearty stew and porridge under swinging carcasses.
Few users of the bridge would ever set foot, either, in Newtown's Metro Mall, the recently built faceless complex for taxis, buses and "formalised informal trading", where some hawkers were locked out last week because they were unable to pay the rent. They would much rather sell their petticoats, oranges, bark, herbs and confectionery on the streets, but that is not allowed, because it is considered a threat to the legitimate store owners. Also, street trading is unsanitary. "We must have order," says Pascale Moloi, the city manager, endorsing the divide that festers below the bridge.
While the end of apartheid has removed the system that used to keep most of the poor in remote rural areas, Jo'burg still finds ways to make them feel unwelcome. During the 1990s, Operation Nude Ants, a crackdown on bye-law violations, put paid to cooking hot meals on street corners or selling livestock in residential buildings. People who take up residence in derelict buildings are still evicted to the "informal settlements" on the city's outer limits. It is acknowledged that apartheid's legacy must be addressed, but Amos Masondo, the city's first executive mayor, says that anyone earning less than R18,000 (just under £1,500) a year has no place here.
The irony is that downtown Jo'burg is now considered the safest area of the city - startling news for those who fled in panic to the northern suburbs during the 1990s, when the stock exchange and several large office blocks were closed.
Some say the decline in crime is due to the departure of carjackers to richer pastures, the installation of closed-circuit cameras and visible policing. Or to the vigilantism that rears its head from time to time: thieves are stripped naked and forced to run for their lives. But the assault rifles and the prison-style bars protecting the liquor stores in the streets vaulted by the Nelson Mandela bridge clearly indicate that our astronomical crime rate is not going away.
If any further proof were needed of that point, it was provided by the launching of a new initiative last week. Carjackings are almost routine - a vital document from the office of President Thabo Mbeki was nearly lost when his spokesman had his car seized by thieves - and many of the vehicles thus obtained are used for another favourite: holding up security vans.
Even Jo'burg decided enough was enough, though, when there were five such hold-ups (or "cash-in-transit heists" as they are called here) in almost as many days. The modus operandi was the same each time: hijacked cars were rammed into the security vans to immobilise them, then chainsaws were used to cut off the roofs. A syndicate is suspected.
Tom Bouwer, general manager of Business Against Crime, one of the groups working to put a stop to the raids, complained that the rate of cash-in-transit heists had now reached two a day. "We usually have about 300 per annum, which is almost one per day," he said, demonstrating what passes for normal crime levels.