8-in W x 8-in H x 16-in L cored concrete block is manufactured for consistent size and shape, Some blocks include a groove molded into the block, designed to function as a masonry expansion joint. One side has a rough, jagged stone-like texture. They are ideal for retaining walls, building facades, and decorative half-walls.

Lowe’s has a similar style for $3.34. I have about 40 blocks. Free of charge.