End of The World is a block that cannot be mined. it is found at Y: 0. This is at the bottom of the Corruption Layer.
End of The World blocks under normal circumstances, appear to be a purple, shiny block. In reality, they are unmineable "glass" blocks, and the purple color comes from seeing through to the purple fog that makes up the corruption layer. They are translucent, and if one shines a beacon facing downward, they can see the beam going down through the End of the World blocks. In addition, If one is far enough away form other corrupted blocks, and has daylight pouring through a large shaft, they will be able to see the End of the World blocks without the purple fog from the corruption layer, making their appearance identical to glass blocks. Despite being at the very bottom of the world, End of the World blocks will not fill the corruption meter at all. A player will only receive corruption from other corrupted blocks. As such, if all corrupted materials are cleared away in a far enough radius, the player will accumulate no corruption, even while standing directly on top of the End of the World Blocks.