A minecraft cave entrance, but an algorithm has smoothed all blocks into a continuous curve. So the hole is round and the terrain has no edges.
https://media.absturztau.be/media/51f5dd65e5a5d03ccf4a0de15b7b81172cd254cc9d309c38a069f74f41a0edb4.jpg?name=7pDS1tV-SG3jpA.jpg