This is a wonderful little map. I really like the border insets and the unique map elements (such as the keep and compass). Nicely illustrated. This is not a criticism so much as a suggestion: the width of your linework is the same throughout the piece, I think that varying the weight of your lines a bit more, and tapering it in places (e.g. such as at the ends of the dune lines) would only serve to further enhance your linework.

Cheers,
-Arsheesh