Johannesburg ready to host the G20 summit? |

In just under a fortnight, leaders from some of the world's major economies will gather in South Africa's economic heartland, Johannesburg, for the G20 summit.

But just a few kilometres from the spruced-up, highly secure venue is a city centre which the authorities are struggling to improve and keep safe.

They face major challenges in cleaning up more than 100 derelict buildings, many plagued by rubbish and open sewage, some of which have been taken over by criminal gangs