There's a hill in New Brunswick, Canada, where something extraordinary happens. If you park your car at the foot of it, and throw it into neutral, your car seemingly starts to roll (completely unassisted!) uphill. Yes, it's real, and, no, it's not for the reason many people think.
In a Kinja discussion, commenter SalBCrumb referenced one of the many explanations people have thrown out for Magnetic Hill's strange (and tourist-drawing) behavior, saying "[It] will actually pull your car up the hill backwards to about 20 mph thanks to the strong magnetic field. Very cool!"
Very cool, indeed! But the real explanation has nothing to do with magnetic fields, and everything to do with the power of illusion.
For an illustration of just what's happening, look at this clever visualization put together by Kokichi Sugihara of Meiji University, which uses the same principle. At first, you see what is a seemingly impossible feat: a series of small wooden balls rolling uphill.
But, do you see any magnets? That's because there aren't any. What you're actually seeing is a clever optical illusion, a fact that becomes instantly clear when you rotate the sculpture and look at it from behind:
Now you obviously we can't rotate Canada's Magnetic Hill around to get another view, but this sculpture gives a better visualization as to what's happening, both on the hill and in people's minds.
People aren't lying or mistaken when they report their cars rolling on the hill. They simply aren't seeing the motion correctly. It's an odd optical illusion that gives them the sense of moving uphill, even though they are actually heading down.
And, for the still-unconvinced out there, even the Magnetic Hill's staff agrees.
Image and GIF made from this video by Kokichi Sugihara