The mapping process for the lands described in A Song of Ice and Fire was similar in most respects to mapping Middle Earth and Beleriand. Fortunately there is a set of sumptuous maps available that identifies all of the locations and it is authorised by George RR Martin himself, so there’s no basis for disputing relative locations.
The only real issue is scale. Martin has deliberately not included scale on the maps because he didn’t want fans to be bogged down in the distances, but back in 2008, he did help us out.
“The Wall is a hundred leagues long. A league is three miles. Go from there.”
So The Wall is 300 miles long. Using this as a guide it is possible to achieve a scale for the rest of the world….with one important condition.
The Wall is one of the more northerly parts of Westeros. You have to be careful when mapping it on a spherical Earth to make sure that the rest of the world doesn’t distort too much while keeping the Wall 300 miles long.
What does become clear is that the distances in ASOIAF are much larger than those in The Lord of the Rings. Frodo’s journey to Mordor is about 1,200 miles, but that’s less than the trip from Winterfell to King’s Landing. When you consider that Essos is probably three times the size of Westeros, you can see we’re dealing with much bigger areas.
It’s a fact that gets overlooked on a regular basis in the TV series where the pace of the story would be constrained if attention was paid to the reality of Martin’s geography. Occasionally it does result in me having a rant.