Incredibly well detailed map! The cities are very impressive. Overall though I found it a bit difficult to distinguish some of the different elements within the map. As jshoer pointed out the trees tend to blend into the mountains. Also, while I like all of the detail when viewed up close the map looks a bit "busy", without much space for the eye to rest. I think a lot of this is due to ho much grass lines there are in this piece. I'd recommend less grass clumps, and perhaps scatter them a bit more irregularly. Another thing that might help readability would be to add more contrast to the piece as a whole, e.g. by darkening the forests and ocean. Please don't misunderstand, I think you've got a wonderful style. These are just a few things I think would improve an already great piece.

Cheers,
-Arsheesh