That is out of bounds to my knowledge. if there is a way to get there I would be interested in hearing it.
This is the closest I could get with the standard out of bounds glitch... Actually, it allows you to get "inside" the wall next to it, which is closer but doesn't make for a good screenshot. I couldn't find any way to get onto the beach. Either way, I'm sure it can't be interacted with. If it was something that could be picked up it would show up in the game code, and it doesn't.