Abstract: This invention refers to a brick that may be used with other bricks having similar dimensions. While the normally exposed sides of the brick are flat, one end of the brick terminates in an angular truncate extension with the opposite end of the brick having a similarly shaped concave recess. The top of the brick has a conical shaped extension on one end and a conical recess on the other end thereof. The bottom of the brick also has a conical shaped extension on one end and a conical shaped recess on the opposite end as previously described for the top. A shoulder extends upward on one side above the top of the brick and downward on the diagonally opposing side below the bottom of the brick. The opposite side on both the top and bottom of the brick has a recess for receiving the shoulder. Holes extend through the brick from top to bottom to receive reinforcing bars therethrough.