newgrange bru na boinne

Newgrange is Ireland's best known prehistoric monument, and one of the finest passage-tombs in the whole of Western Europe. Foremost among the passage-tombs of Europe.
The almost heart-shaped mound is about 36 feet high and about 300 feet in diameter. Carbon dating has shown that the tomb was constructed around 3100 BC and is thus probably centuries before the Pyramids.
The magnificent entrance slab is a decorated stone covering a small box over the passage which allowed the sun's rays to penetrate to the centre of the burial chamber as they appear above the horizon on the morning of 21 December, and one or two days on either side of it.
It is 'one of the most famous stones in the entire repertory of megalithic art. The triple spiral, found only at Newgrange, occurs both on the entrance stone and inside the chamber.
The passage is long, over 60 feet, and leads to a  burial chamber with a corbelled roof which rises  to a height of nearly 20 feet. A number of the stones bear decoration, such as spirals, zigzags etc.
Recent excavations have shown up some clever techniques used in building the mound, particularly the stone packing above the chamber, so that water filtering down from above could be drained off rather than dripping into the chamber - which remains remarkably dry.
Standing upright in the earth outside the base of the mound are large boulders up to 8 feet high, of which 12 out of the original estimated 38 survive. The revetment of large horizontal stones surrounds the base of the mound and many of these are also decorated with geometric designs. Excavation has shown these stones to be later than the great mound.

There are two related tombs in the vicinity, Knowth and Dowth. There is also a wealth of history in the surrounding area, including the Hill of Slane.