I can't believe I wasn't bit by that black widow spider! The third and final retaining wall went much smother than the previous two (done in previous episodes) because I had learned from my mistakes. The retaining wall is important because the walls that will be built upon them will be incredibly heavy. The process of adding the water and compacting the dirt behind it is a process I didn't really show with the other two walls but I did do it to those too. The reason I added sod with grass to the outside is to stop erosion on that side of the wall, water coming off the roof had already started to eat away at a portion of the wall. Also this was my first attempt at making char cloth and it worked great! I left it in the fire for about 20 minutes but I think next time I'll leave it in there a little longer.