[She peers around his shoulder to see which map he's looking at, and nods.] That is the most complete map of the isles I've seen, in my own research. The others in the book are simply details on the cities, all the way down to an in depth look at roads and streets within the the most populated part of the cities.

Were you thinking it was larger? It's possible. Probable, even, but this is all that is recorded.