Abstract: A beach building block which is formed with a single passageway extending in a vertical inclination therethrough and which presents a solid wall at the rearward side of the block for containment of sand and the like behind the block and thereby build a beach. The blocks are positioned in row parallel to the shoreline, and while they permit the wave to flow through the block, they dissipate the energy of the wave, and they also retard the return flow of the water with the suspended sand, and thus the beach is built behind the block by the deposit of the sand.