Started making some rocky formations out of paper-pulp, glue, and kitty-litter... Don't use kitty-litter. lol...
It sounded great, looked great at first, then it shriveled into little smushed raisin shapes over night. hahaha.
Now, I'm using wet clay coated in a 50/50 mix of water and glue, and mortared with a paper-pulp mix.