Police and guards at North Mara have been accused of killing dozens – possibly hundreds – of locals

by Jonathan Watts in Tanzania for the Guardian UK

When safari tourists drive to the Serengeti national park in Tanzania, few realise they are passing one of the world’s most contentious goldmines.

From the escarpment above the plain, the North Mara facility is so large that it at first resembles a bare hillside. But look closer and the artificial mound is made up of tiers of reddish brown earth, from which a thin grey plume of smoke drifts up to the sky.

Nearer still, you find a vast tailings reservoir filled with contaminated wastewater. Locals live in huts under the shadow of its mud and rock banks.

Welcome to North Mara, one of the biggest mines in Tanzania, which since 2006 has been operated by London-listed Acacia Mining and predominantly owned by the world’s biggest goldmining company, Barrick, a Toronto-based firm that holds a 63.9% stake.

For the past two decades, this mine has been a place of danger, extreme violence and allegations of environmental contamination.