The Italian creative studio Invasione Creativa took a bunch of famous paintings and used voxelizing techniques to transform them into chunkily-pixeled relief-maps. The Mona Lisa, in that video above, becomes a landscape of colorful hill, valleys, and peaks.
The result is terrain that is super reminiscent of Minecraft — these would make pretty fun maps for that game.
They don't really explain how they did these translations, though. Were they actually scanning the 3D topography of the paint as it was laid down on the canvas? Or just converting different colors to different heights, in a sort of educated guess? I think the latter — though wow, if they actually pulled off the former, it'd be super cool.
Either way, these are fun to look at — Invasione Creativa posted dozens of these images to their page here.