OK, I am finally done with my "4 hour time limit cave map", Cavernes de DuFlor
It took me 3 hours and 46 minutes in total, though drawing took about 1.5 hours, the rest I spent coloring this in Xara Xtreme.
I tried a 3D version, but I couldn't create a cut-away to properly show the caverns I created - not in time anyway. So I went for hand-drawn afterwards. And this is my final result.
Maybe I need to add the scale and post again, but 1 square = 5 feet is the scale.