This idea came from this super spectacular idea here. Mine is way scaled down compared to the awesomenes that the idea came from but oh well. I must apologize for being terrible and giving tutorials. I don't think to take pictures a long the way until it is done. I found the pack of dinosaurs for this in the dollar bin at target.
First thing I did was cut out to pieces of brown felt for the ground you can make them as big or small as you want.
Cut out the shapes that you want for your grass, water, and whatever else you would like to add. That brown bump in the back of mind is supposed to be a cave but its a little flat. Sew these pieces to your top piece of felt. Also if you would like yours to fold up then put a piece of velcro on each side (You can see mine in front of the the cave and behind the water).
For the trees on mine I glued them to a piece of felt and then stuck some velcro on the bottom of it. That way when it gets folded up you can take them off an lay them down.
The next step is sew the two pieces of the big felt together. I sewed mine wrong side together and then turned it inside out but if I were to do it again I would just put them together right side and sew around the outside since the felt won't fray.
This works great fold up into your bag and take to restaurants especially if you have a toddler that isn't terribly interested in the crayons and paper.