This is guesswork but the cave is so near John Paul's home and it is such a perfect place for small boys to play at making a camp that I am sure that something like this happened. Anyway look at the photographs and judge for yourself. The cave is not what we usually think of when we talk of caves. It is actually a latge rock some distance from th shore. The cave is actually a cleft or tunnel through the middle of the rock.
Gorse bushes grow on top of it.
There is a beach of sand and crushed shells behind the rocks. There is a small hollow behind the cave itself. The following photos show the beach behind the cave. The photos are taken both from the land and the sea side. Here is the small hollow behind the cave.