We've talked about the Outerra engine a few times here on Kotaku, and every time we do, someone invariably asks "but what is this actually for"? Well, here's one application: it's great for making a 1:1 recreation of Middle Earth.
The Middle-Earth Project is looking to rebuild all of Middle Earth in the virtual space. All of it. Not some curated highlights package, not a small slice of it, but the whole damn thing, from Hobbiton to Mordor and everything in between.
It's still a work in progress, so some areas like Mordor (which needs custom terrain the standard engine can't create) and Moria are unfinished, but even what's there is breathtaking to behold.
Their work is being based primarily on existing maps of the land, whose details - like everything else in Lord of the Rings - were penned pretty exhaustively by author JRR Tolkien.
Note there's no game to it. All you can do is fly around taking it all in. But even that's a blast.