Behold: the world’s largest meatballs. Sadly, no amount of spaghetti sauce will make them edible. Known as Karlu Karlu, these boulders in the Northern Territory of Australia formed over 1500 million years ago from an upsurge of molten rock that cooled and became solid beneath a layer of sandstone. Well, that’s the scientific explanation.

In Aboriginal folklore, these boulders are known as the Devil’s Marbles. Tampering, damaging or removing the boulders could cause life threatening consequences. Despite this, a boulder was removed without permission in 1953 and taken to Alice Springs, where it was placed on the grave of Outback legend John Flynn who founded the Royal Flying Doctor Service.  54 years later, the stone marble was returned to the Alayawarre people and a new boulder replaced it.