Raw Materials: 6 bags of .5 cu ft of drainage gravel (Lowes)
42 Retaining Wall Blocks (Home Depot)
Angle Grinder with concrete-ready blade (only needed if you get blocks that do not have two level faces)
Step 1: Place 14 Blocks in Circle
I would also like to note at this point that you could use any number of blocks for different size fire pits and 12 would actually be the easiest to set up because the angles work the best. I chose 14 simply because I liked that size.
Step 2: Remove Blocks, Dig, and Lay Gravel
Dig a hole in the center of the pit about 20 in deep and 15 inches in diameter. Fill this with gravel for drainage.
Note: My pit was located in an area with wood chips so the area already drained well, hence less drainage rocks were needed. If you have clay soil I would advise following the instructions from this old house on the trench/ hole depths. Or you can use your own discretion.