We landed at a little bay near Punta Morro Prieto with the usual berm blocking the sea from two salt flats. These salt flats were still salty and had a few brine pools in them. When I went for a walk the salty soil had funny ridges all over it that crunched underfoot. These turned out to be the houses of little fiddler crabs! When I realized this I turned back, tip-toed out and tried to leave with the minimum of home-wrecking. There were two salt flats behind this beach because they were separated by a tall bermy thing, perpendicular to the normal beach berms. It was ten meters tall and flat topped. It looked like a man-made road fill, almost smooth on top with very steep sides. It snaked a few gentile turns down from the hills, getting shorter as it came. It seemed to be made of volcanic red cinder brick-like rock. But it was filled between the rocks with fine sand. Now was such a structure made? My best guess was a lava jumbles that was submerged for a while so the water had time to fill the cracks with sand. Then it was uplifted again.