Part of this ancient landscape is protected within the Mapungubwe National Park, which contains archaeological evidence of a sophisticated Iron Age trading kingdom, including palace sites and dependent settlement areas.

The Sunday Independent reported that the UN Educational, Cultural and Scientific Organisation (Unesco) has sent two missions to Mapungubwe to assess the impact of proposed large-scale coal mining in the area.

Opencast coal mining had resumed in Vele, with a limited version of the open pit that coal miner Coal of Africa planned once full production was reached. The Vele colliery is located on Limpopo's northern border.

"Yet, the visual impact of even this 'small' intrusion in the landscape is substantial," Unesco was quoted as saying.

The mine would not only destroy the cultural heritage which happened to be in its way, but also modify the cultural landscape. Unesco did not agree with a heritage assessment which found the impact of Vele would be minimal.

The site had "seriously deteriorated" and Mapungubwe risked being placed on the list of world heritage sites in danger, the weekly reported. It recommended that the buffer zone around Mapungubwe be increased, and asked South Africa to submit information on Mapungubwe's boundaries by February next year. It wanted South Africa to ensure that mining activities did not affect the site's value.

The environmental affairs department reportedly said it would work with Unesco's world heritage committee.