Thank you for suggesting the image search -- I had been imagining a castle-like wall, and seeing the stacked tetrapods [0] was really eye-opening. (Apparently

Thank you for suggesting the image search -- I had been imagining a castle-like wall, and seeing the stacked tetrapods [0] was really eye-opening. (Apparently it helps dissipate the wave energy.) 0: https://en.wikipedia.org/wiki/Tetrapod_(structure) https://en.wikipedia.org/wiki/Tetrapod_(structure)