Johannesburg tour.

We saw a lot of Jo'berg today. It is a large sprawling city with a remarkable mélange of architecture, all pointing back to 1886, when a reef-load of gold was discovered.

We were given a 6-hour tour of the town by Chris Green, a native of Jo'berg, who has watched the city change profoundly in his 50-odd years. He actually started the tour at 2.2 Billion years ago, when the bolide impact that is responsible for the modern shape of the geologic "reef" that is the source of Jo'berg's rich gold deposits.

The gold was discovered around 1886, and almost every aspect of Jo'berg can be traced back to this deposit, from the shape of the city to the colonial, art deco, and modern architecture. But just as gold mining defined the city for the first 100 years, it has been Apartheid and the post-Apartheid re-alignment that defines how the city operates now.

We visited a shopping centre which was once considered "failed" as the White shoppers did not frequent it, but it was bustling with the Black middle class. There was even a Santa on site, granting children wishes. It is the Black middle class that is building the City now.

But the gold deposits are never far away. As few as 20 years ago there were underground mines operating in and under the Central Business District, and the sepia-toned ridges surrounding the downtown are not only the waste rock of mining's past, but are being re-worked, reprocessed through more efficient gold-extraction methods, and re-claimed as commercial, industrial, and residential space.

At the same time, old mine workings kilometers under the City are abandoned, and filling with groundwater. The groundwater is becoming acidic through its exposure to metal-rich ores, and present a future threat to the fresh water supply of Jo'berg. This has been recognized as an issue for decades, and may come to a head in the next 5 years. But like most pending environmental disasters, few concrete actions are being taken to address this issue.

Aside from acidic groundwater, there are also the expected structural issues with building a modern city on top of a century of mine workings. Chris showed us a special site in the foyer of the Standard Bank Building, where an 1880s mine shaft was discovered during the excavation for the building, and instead of plugging the hole with concrete, the Bank decided to preserve the original mine workings an the basement to the foyer as a museum to the city's past.

Finally, Chris took us to the Constitutional Court, built on a hill overlooking the City, symbolically built on the site of one of the most notorious prisons in South Africa. A place where people's rights were lost to unaccountable imprisonment and torture, now a place where peoples rights under a new Constitution are enshrined and protected.

It was a great tour, and I am not doing justice to Chris' encyclopedic knowledge of the City's geology, architecture, history, and culture. It was a day well spent. Followed by a great dinner in Melville. A great first day.