This is what you get when you take the most detailed speculative map of George R. R. Martin's A Song of Ice and Fire series (a map Martin himself called "very handsome") and combine it with a scrupulous account of the characters' travels throughout the series.
Reader, prepare yourself — this thing is epic (and obviously FULL of spoilers).
The original map is the work of one serMountainGoat, and is certainly impressive in its own right. You can read more about its creation (and Martin's reception of it) here; but redditor PrivateMajor really brought it to another level by color-coding characters' rovings through Westeros, Essos and beyond. [Click here for a very, very hi-res version]
"I'm a huge ASOIAF fan," PrivateMajor told io9. "I started reading the books after I saw the first season of the show. I got incredibly into the book, and I absolutely loathed to read a character name or location that I didn't remember completely."
So he took matters into his own hands by perusing the books, "constantly referring to maps and background information on characters so I fully knew everything that was going on." He continues:
By the time I finished the series, all of my books each had highlighted drawings of certain character travels in the individual book maps. I made these as I went along to keep visual track of where everybody is, because by the last book it gets incredibly confusing.
This map was my first attempt at merging all of my little maps together, with some additions for more minor characters.
Color us impressed. Based on the discussion that this map spawned on Reddit, an even cleaner version may be forthcoming (here's a preview of what it might eventually look like). We'll keep you posted.
And for all you dataphiles, also worth checking out is the Google spreadsheet PrivateMajor is using to keep track of all the characters and chart their respective journeys.