Oranjemund, Namibia. It seems to be the largest diamond mine vehicle graveyard, and yet there are barely any pictures of it. Satellite photos of the area could let you guess how big it is. The mine owned by De Beers is reputed to have the largest private earthmoving fleet in the world.
From the texts I have found here and there, my understanding is that that people are not allowed to visit those the area for safety reasons, hence the lack of available photos.
This tank was last used in industry, not war; after World War II, the diamond miners of Oranjemund used surplus tanks to bulldoze sand.
Once a machine has been used for diamond harvesting in the De beers mine, it won't leave the mine anymore, even after it's Obsolete. Machines of any types have been piling up in the graveyard since the 1900's. The reason seems to be that people could find diamonds trapped in those old machines. I don't know why the company do not dismantle them in search of possible lost gems though...
A map of the graveyard, each point is supposedly a vehicle