Abandoned giant tetrapods, leftover from a major coastal freeway construction project on the "Ile de Reunion" (the French "Bourbon Island") - Indian Ocean
"Tetrapods were designed to remain stable under even the most extreme weather and marine conditions, and when arranged together in lines or heaps, they create an interlocking, porous barrier that dissipates the power of waves and currents." ( www.japantimes.co.jp/life/2007/07/22/general/tetrapods/#.... )
Infrared film