Grootslang

A giant snake of South African folklore, said to live deep in a cave in the Richtersveld and, in later retellings, to guard diamonds. A prospector's 1920 memoir describes dynamiting the water where it was said to live and finding only fish.

Grootslang means "big snake" in Afrikaans and Dutch. Wikipedia calls it a legendary creature said to live deep in a cave in South Africa's Richtersveld.

The prospector Fred C. Cornell describes in The Glamour of Prospecting (1920) how his party made up dynamite charges with fuses and detonators and threw them as far out into the water as they could, with their guns ready should the snake be home and resent it. The blast churned up the water, but no snake appeared: only a few small fish, springers and barbel.

Lawrence G. Green, in Where Men Still Dream (1948), reports a legend that a hole in a remote corner of the Richtersveld, known as the Wonder Hole, or the Bottomless Pit, is where the diamonds come from. He writes that local people held the dark cavern to be the Grootslang's home, which he links with the Orange River, and were unwilling to guide expeditions there.

The story kept growing. A 1998 Augusta Chronicle piece retold a legend of a cave full of diamonds waiting for a bold adventurer, guarded by the Grootslang, pictured as a 40-foot serpent with great jewels where its eyes should be.