This is the entrance to Newgrange. The largest of multiple ancient Irish passage tombs in the Brú na Bóinne area of Ireland. It is over 5 thousand years old. The hole in the middle is the entrance that leads to a narrow passage to the tomb area. The hole above the entrance allows a shaft of light to illuminate the tomb on one day of the year, the Winter Solstice. It is quite a mystical place.