A friend needed a map for a 4 way team game and to accomplish that edited Riverlands to be non-wraparound and have ~20 land provinces per player for 8 players.
So, base map graphic is by me, .map file and province borders are by Rumahinen.
I got to say the new borders look a lot smoother
EDIT: The big 1-4 numbered zones don't exist on the map itself. I was too lazy to get a new screenshot.
I personally won't link to Dominions 3 content made by me any more and I hope no-one else will either (old links are fine, whatever). You should be able to find them or most of them by asking on IRC or googling the other forums