Choose the location of for the fire pit. It should be level ground and away from buildings and other man-made structures. Do not build your fire pit beneath trees.
Put on a protective helmet, protective mask and welding gloves. Cut about 26 inches from the top of a 55-gallon metal barrel drum using a plasma saw. The part you cut off will be the fire ring. If you don't have a plasma saw, take the barrel to a welding shop to have the barrel cut. An option is to purchase a metal fire ring.
Dig a hole the size of the fire ring. Make the hole deep enough for the fire ring to protrude only about 8 to10 inches above ground level. Tamp the soil in the hole with a tamper to make it level.
Place the fire ring in the hole with the newly cut edge downward. Use loose soil to fill extra space around the outside of the fire ring so that the fire ring is positioned securely.
Line the bottom 6 inches of the hole inside the fire pit with gravel.