WIP 4'x4' Fantasy board

Over the past week we have been working on a new Fantasy style game board. It is far from done but we both have very high ambitions for this project.

So far we have a 4' x 4' x 1-1/2" foam board (made from a 8'x4'x3/4" pink insulation foam from the hardware store). Tools we used where a small hobby saw, the large straight blade in the pictures, a cheese grater (works wonders on large corners), and spackle.
As the pictures in the slideshow show, we plan on incorporating a river, swamp, mountains, and road. We have also though about making a forest and some ruined buildings.
As it is right know all we have done is cut out the preliminary shape and completed some basic sloping to transitions into the many levels of this board. Our next step will be to finish the sloping and mountain ranges for one of the corners and to add some text using rocks and sand.

Because this project so large and we both want it to turn out better then we could imagine it will be a long while before we are 100% complete with it.
For the mean time keep posted for other, smaller terrain, projects and some battle reports with the new forest terrain we just finished.