No, this isn’t a quarry discard pile, but an entirely natural phenomenon. And it might be bigger than this photo conveys; the rock pile is over 2 km long and rises 350 m above the surrounding plain.
The rocks are giant granite boulders, some reportedly as large as houses, and the mountain is a great pile of them with the hollows between extending deep within.
You can see it is granite from the grey rocks in the foreground. The black colour comes from algae growing on the rocks.
An early geologist climbed the mountain, but rumour has it that others have tried and disappeared within never to be seen again! Climbing is discouraged.
The Black Mountain Boulder Frog, the Black Mountain Skink and Black Mountain Gecko are found nowhere else.