Billions of lasers directed at the ground in South Africa's Suikerbosrand Nature Reserve have revealed a once thriving city lost to the centuries. The metropolis, known as Kweneng, is overgrown with scrubby vegetation from years of disuse, but in its prime it comprised around 800 homesteads and over 10,000 people.
The city was at its peak between the 15th and 19th century, before civil wars led to its destruction and abandonment. Scientists have known about Kweneng since the 1960s, but the landscape was too thick with vegetation for proper examination. The research was first reported on months ago, but more details have come to light since then.
Professor Karim Sadr of the University of the Witwatersrand and his team decided to harness a relatively recent form of laser technology called LiDAR to achieve a more comprehensive look. This tech converts billions of laser pulses beamed at the ground into a high-resolution image by calculating the time it took for the lasers to reflect back to the sensor. This provides scientists with a 3D map of the topographical landscape hidden beneath the bramble and brush.
"A resilient myth is this land was empty when the first Europeans arrived in the 1830s and so they had the right to claim it as their own," said Karim Sadr to IFLScience. "This is of course nonsense and is disproven by a great deal of historical and archaeological knowledge. But alas, that knowledge does not seem to filter to the general public via school history lessons. This is lamentable, but the current exposure given to Kweneng by the media may go a little way to help resolve this matter."
The city once covered 20 square kilometers (7.8 square miles), transforming what the researchers thought was a rather modest gathering of stone huts into a much larger hub of activity. The metropolis was occupied by the Tswana, a group who still live in Botswana, South Africa, and nearby regions today.
"Judging by contemporary Tswana capitals of kingdoms farther west, which were visited by European travelers in the first quarter of the 1800s, Kweneng would have been the capital of a city state, with a territory that may have stretched a few dozen or more kilometers around it," said Sadr. "The ruler was a king and the royal family would have constituted the noble class and the core of the Kingdom. The king had absolute power, but the population could always vote with their feet and leave to join other kingdoms if they were unhappy with the royalty."