The top of this rail has seen woodier days. You can get a sense of the tree rings through that slit. And facing the photo there’s still some “bark” left. I find it fascinating that the aggregate used in the cement is so big. What do you think caused the “bark” to wear away? Too much sand in the mix? Acid rain? (I hope not the latter, and you’d think if that were true there would be a lot more damage.) This photo was taken in a different part of the trail, maybe a different sakan company did this work.