Bryn Celli Ddu (Welsh for the mound of the dark grove) is probably the best known prehistoric site on Anglesey and an excellent example of a passage grave. The tradition of building passage tombs spread up the Atlantic coast from western Spain to Britain and Ireland about 5000 years ago, towards the end of period of megalithic tomb building. In Ireland there are about 330, mainly in the east of the country, with the pinnacle of passage tomb building being the great tombs at Newgrange. On the other side of the Irish sea the best surviving examples in Wales are Bryn Celli Ddu and Barclodiad y Gawres on Anglesey.
Passage graves consisted of a passage leading into a central chamber and then the structure was covered with a large mound of stones. Details in the design vary from tomb to tomb and and the passage was often deliberately aligned with solstice events, so that the rising or setting sun would shine down the passage and illuminate the chamber at a precise time of the year.
Bryn Celli Ddu is in the care of Cadw and there is a small park with interpretation boards telling you about prehistoric life on Anglesey and other sites you can visit. On the other side of the road a footpath enclosed by hedges leads up through the fields to the site.
As you emerge from the footpath and go through the gate you are facing what looks at first glance to be the entrance to the tomb – a concave area revealing a couple of orthostats topped by a roof slab and facing this on the edge of the mound, is a highly decorated standing stone.
This is actually the rear of the chamber, which was left exposed to allow some light into it. Personally, I would have preferred it if they had fully enclosed the chamber as the light detracts from the sense of mystery and other-worldliness you get when entering a dark tomb.
The entrance and the 8m long passage into the chamber is on the opposite side of the mound and what you see today is the result of excavation and reconstruction work in the 1920’s. Before this, there were stone remains but no mound. When excavations were completed, the chamber and the passage were covered by a mound, thus recreating a tomb similar to what it would have looked like when it was built in the early Bronze Age and giving visitors the experience of being able to enter a passage grave.
The passage is aligned so that the sun shines down the passage and illuminates the chamber at sunrise on the summer solstice.
Rather than replicating the full-sized mound which would have had its chamber in the centre, the covering cairn here only reaches as far back as the rear of the chamber and is much smaller than the original would have been. The remains of a ditch and outer ring of stones show the size of the original monument.
Bryn Celli Ddu has a fascinating history, probably going as far back as Mesolithic times and over the past few years it has come to light that Bryn Celli Ddu doesn’t stand alone but is part of a prehistoric ritual landscape. Archaeologists have uncovered rock art, flint tools, pits containing pottery deposits and evidence of more burial mounds.
In Neolithic times, long before the passage grave was built, a stone circle stood at this site. This was surrounded by a ditch and an embankment. Sometime during this period as a henge, a pit was dug in the centre of the circle and a human ear bone placed in it. The pit was then filled in and covered with one or two stone slabs. During excavations, a decorated stone slab was found next to the pit remains. The stone now standing outside the rear of the chamber is a replica of this and is next to the spot where the pit was found. The original is now in the National Museum of Wales.
About 1000 years after the construction of the stone circle, it was destroyed and a passage tomb was built on the site. When the tomb came to the end of its use a stone was placed at the entrance to seal it up. There was some evidence that part of the passage was infilled with smaller stones and some human bones placed in among them.
One of the most unusual features of the tomb is a free standing pillar which is situated within the chamber. This is made from the local blueschist stone and has been carved into a smooth shape.
More images of Bryn Celli Ddu