In a way, the mere existence of Balanced Rock also seems like a prank, either geological or cosmic. The enormous boulder looks like it had been photoshopped onto the landscape, or photographed mid-roll, or carefully placed by aliens. But it’s no hoax and there’s no sorcery to it. Rather it is a prime example of a whole category of geologic formations called ‘precariously balanced rocks’ -PBRs, for short. They’re exactly what you might expect. ‘It’s a rock balanced on top of another rock,’ says Mark Stirling, who studies PBRs at the University of Otago in New Zealand.
— Why Scientists Fall for Precariously Balanced Rocks in Atlas Obscura