That right there is the URL to this website encoded as a QR Code and embedded into the map on my Minecraft server. The image is from the rendered map of the surface and it is readable. One person was even able to read it with their phone in-game while a cow was walking on it!
For anyone curious, the black is made of obsidian and the white is made of snow blocks. I took about 15 trips with an inventory full of buckets to pour lava into the black areas and convert it to obsidian.
Anyway, the next step it to make one in real life….