The entrance slab to Newgrange tomb, Ireland.

This Irish megalithic stone, about 4500-5500 years old, is 10 feet by 4 feet in size and 5 tons in weight. It is one of the most famous rocks in Ireland and stands—about an hour from Dublin—at the entrance to Newgrange, a “passage tomb” 300 ft. in diameter and 40 ft. high that is older than the Egyptian pyramids and Stonehenge. The carved spiral design, though more ancient than the coming of the Celts to Ireland, was often copied by them and became one of the legendary Celtic designs.

(Source: collective-history)