It is a decapitated dune. Lopped off the top
It's a decapitated dune with a bunch of work at the bottom left of it.
When we first found the site for #13, we took Mike Keiser out to see it, and he asked right away how we would get back into the rest of the golf course. I hadn't really thought about it, but sort of assumed that we would play down into the land where the sixth hole at Old Macdonald is today ... but then Mike asked if we could play a par-3 along the dune tops so we could still see the ocean from tee and green.
We ran with that idea; but it took a lot of work because that dune ridge was VERY sharp and VERY high off the ground. The green now is maybe ten feet lower than the top of the ridge it was built from, but when we had just done that part, it fell off almost as deeply to the left as it did to the right! I imagined people going back and forth over it for an hour and then giving up. So, we made a big cut behind the thirteenth green, to get a road back around to it, and we brought all the sand around and built all the features to the left of #14 green (the bunker, the little dunes that hold it up, etc.), and we raised the lowest area to the left around six feet, too, so that you would have some chance of playing back onto the green from that side.
Don't miss right, we couldn't do anything about that side without spoiling the beauty of what God put over there.