"Person Makes Impressive Thing in Minecraft" stories are old news these days -- it's what Minecraft's sort of for, after all.
But the UK's national mapping agency Ordnance Survey has done something a bit more impressive than making a really nice-looking church: they've mapped 220,000 square kilometers (nearly 84,950 square miles) of the United Kingdom's real-life landscape -- specifically, all of mainland Great Britain and its surrounding islands -- using Minecraft's tools.
The world was created in two weeks by intern Joseph Braybrook, working with Ordnance Survey's Innovation Labs team, and makes use of OS' own digital map products OS OpenData. Rather than building the entire map by hand, which would have taken considerably longer than two weeks, Braybrook and the team wrote a program to convert the OS' own data into Minecraft's "Anvil" world format. Once the program was created, it took seven hours to generate the entire Minecraft world, which is nearly 4GB in size.
Specifically, the program would load height information from the OpenData files, then analyze small areas of map image files to determine the material of each block, with different materials representing different map features. Freeways (or "motorways," if you want to be all British about it) are represented by blocks of diamond, for example, major routes (aka "A roads") by blocks of emerald, lesser "B roads" routes by pumpkins, and minor roads by gold. These materials were chosen due to their similarity in color with real OS maps, on which motorways appear in blue, A roads in green and so on.
Each Minecraft block represents a ground area of 50 square meters, so the world is more of a scale map than a one-to-one recreation of the whole of the UK, but it's still an impressive achievement, made up of some 22 billion blocks in total. The reason for scaling down the size was primarily to ensure that high areas such as the mountain Ben Nevis -- the highest mountain in the British Isles at 1,344 meters (4,409 feet) -- could fit in the game's 256 block height limit while still allowing for low-lying coastal features such as cliffs.
This isn't the first time geographically-accurate information has been loaded into a video game, of course -- Microsoft's Flight Simulator, for example, has been devouring hard drives for years with its height-mapped, satellite-accurate, "photorealistic" terrain data for years now thanks to the efforts of its developers, hobbyist modders and third-party commercial add-on producers -- but this project is an impressive example of the potential scope of Minecraft worlds specifically.
If you'd like to play around with the new map, you can download it from the OS' official site, which also provides coordinates for a number of landmarks around the country. The download is about 345MB, but it will uncompress to approximately 3.6GB in order to be usable in Minecraft, so be sure to have enough space available. The team also recommends having at least 4GB of RAM for the best performance.
Now go fulfil your lifelong dream of digging a really big hole in the middle of London.