Do you think it was really built this way or something went wrong in its reconstruction? To be fair a number of monuments on the island do use the natural rock features in construction so possible
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Erm, unusual architecture there. I bet they have drawer full of leftover bits they couldn't work out what to do with.
Definitely a bit of an oddity. Believe the capstone was laying there and they simply propped it up (At least I think that is what they were inferring on the MP)