Maps of Barsoom are always fascinating. Given the way the original books were written ERB didn't adhere strictly to an accurate map and instead chose to go wherever the narrative took the story. This resulted in locations and distances that don't match up when plotted out on a map.
To further complicate matters, no accurate map of the actual geography of Mars could even begin to be constructed until 1971 with Mariner 9, and it took decades to map out the planet in any detail. So combining this knowledge a lot of interpretation has to be made.
Since working on Warriors of the Red Planet and attempting to make sense of all of this in order to make a useful and semi-accurate map I've become a bit of a connoisseur of Barsoom maps, gathering from wherever I can find them. So I was pleasantly surprised to find this map of Barsoom from Punch Magazine 1956. In many ways it is the best way to tackle the subject as it is very illustrative and conceptual without trying to be too precise in any way. And it has a great aesthetic.