Alright so how about a field that was all trenches and burms?
I would dig a trench and at certain sections I would stack two pallets (vertically) against the side of the trench and on the outside of that I would pile up extra dirt for the bunkers.
I want to use trenches because they are well free. Totally free.
Any ideas on how I can utilize trenches and any free (or cheap) supplies other than old furniture?