• (optional) a shovel;
• a whole lot of stone blocks;
• a set of wall caps;
• decorative rocks;
• a fire ring;
• wood;

Start by marking out the location and size of your square. Then, starting at the corner, place the corner block. Next, you will have to cut a block at the three quarter length and put the cut-end against the corner block in order to create the actual corner of the pit. Use a square to align the blocks and make adjustments if necessary. Build out from the corner you just made in both directions, placing the blocks in the desired pattern. At the next corner, use the small block which you cut earlier to make the corner. Start the second layer in the same way, but alternating the colors of the blocks used. You could create your own custom pattern, if you wish. Finish the whole structure with wall caps. Place the first wall cap so it overhangs slightly with the long and short ends facing outside of the corner.

Place the other caps in an alternating pattern. Due to the shape of the caps, you will end up with some gaps on each side. Fill these later on with some freshly cut pieces of caps. You don’t need to glue all the blocks together. The raised rings you put on afterwards lock them in place. But securing the caps helps tie things together as well as keep the caps from moving if you want to sit on the wall. Use flexible concrete adhesive for this last step. Add decorative rock to the bottom (inside) of your pit. Place in the fire ring. Add some wood and start your dreamed of fire.