In The Hobbit and The Lord of the Rings, British author J.R.R. Tolkien created a fantasy world called Middle-Earth for his dragons, elves, dwarves, and wizards to inhabit, but he only ever rendered it in text. Now, a team of Danish programmers is taking Tolkien's descriptions of Middle-Earth and rendering it on computers, on a truly planetary scale.
The scale model is called the Middle-Earth Project, and it is so epic in scope that you can see the Eye of Sauron from space, yet so finely detailed that you could zoom from space right into Bilbo's Hobbit hole. It's all accomplished with Outerra, a middleware graphics engine that specializes in letting programmers model terrain, flora, and water using relatively sparse data sets through the use of fractals.
J.R.R. Tolkien wrote thousands upon thousands of pages of fiction, lore and notes that takes place on Middle-Earth, but on the scale of planetary models, that's not a lot of data. For Outerra, though, this corpus is enough to extrapolate a pretty detailed model of what Middle-Earth would look like from space.
It's all a work in progress for right now, and there are a few things the Middle-Earth Project gets wrong. For example, Mordor in Tolkien's universe is a barren, nearly uninhabitable land filled with lava and ash, but Outerra is only rendering it as a desert for now. Over time, the developers hope to create such an accurate model of Middle-Earth that you could tour the mines of Moria if you wanted to. Just don't delve too deep.
If you'd like to explore Middle-Earth for yourself, you can download the simulation here.