 Have you ever wondered what lies beneath your feet? Well today I'm going to take you on a journey to the most inaccessible place on our planet, right to the very centre of the Earth, to the Earth's interior. So the Earth, if we're looking inside it, you can think of the Earth just like an onion. And when I mean it's just like an onion, I mean it has layers, many, many different layers. Now an onion, all the layers in an onion are, well, onion, and they're all the same thickness. In terms of the scale of the layers inside the Earth, it's actually a lot more like a peach. So I pre-cut this, and I'm just going to, oh, it opens perfect. So in a peach you have the stone, then you have the flesh, and then you have this very thin skin on the top of the peach. Now that's just like the Earth. So at the surface where we live, we have the crust, which is like the skin on this peach. And that's the thinnest layer. It's only six kilometres in the ocean, and maybe a few tens of kilometres thick in the continent. But in the scale of the Earth, it's just like the skin on that peach.