The Mitchell River in Australia has a tributary called the Woolshed Creek, which flows by a cave called the Den of Nargun. But what, I hear you ask, is the Nargun?
The Nargun is a creature in the lore of the Aborigines. It is composed partly of flesh and partly of stone, is female and is of humanoid configuration. It was known to abduct humans. It was difficult to defend yourself against for, should you cast a spear or boomerang at it, once it struck its target it would come flying back at the assailant.
In fact, the cave seems to have been used for women's initiations. Perhaps the Nargun was invented to keep intruders away.
Below, you can see a picture of the cave.