As you can see this build is made out using recycled materials, I didn't had to buy anythings, (without counting glue/paint, but I always have it) all stuff that I had in the house.
The base is made out of three layer of cardboard, from a box
For the ground/dirt. I drink espresso coffee, and the "used" coffee, looks good for make dirt. So I glued it to the base and after I seal it and painted/washed. I seal it because I don't know how it will react in the future, and I don't want have surprises...