Statues of Cromm

Surrounding the cave of Cromm Cruac are statues with a design I know I have seen before, but I can't place where. I asked a friend and he said he's seen them somewhere also, but also couldn't place them. The only thing that comes to mind is illustrations or photographs that were in some of my primary school history books, back when we learned about ancient Irish history. The statues from the film are obviously inspired by something real.

Does anyone know what I'm talking about?