funeral practices, but in all cases re-using the tomb, and clearing aside the old remains. At the end of its period of use the tomb was 'closed' by means of a large stone set across the entrance, between the two portal stones. Archaeology The earliest archaeological descriptions date to around 1800. In 1796 it was included on a list of Anglesey cromlechs in the Cambrian Register. In 1802 Rev John Skinner made a "Ten Days' Tour Through the Isle of Anglesea", an account of which he wrote up, but never published, describing the numerous archaeological sites he visited. It was finally published as a supplement to Archaeologia Cambrensis in 1908. On his visit to Bryn Celli Ddu, he was told how the passage tomb had been discovered a generation before, by a farmer looking for useful stone. The sight of the pillar stone had initially unnerved the discoverer, but the prospect of treasure tempted him back, and he uprooted the pillar. Having suffered depredation of the more movable stones of the site, the monument was excavated by W J Hemp in 1928–29. He revealed much of the sequence of use on the site, and found the 'Pattern Stone'. It has since been moved to the National Museum of Wales and replaced with a replica standing outside the back wall, but within the area of the original mound, and close to the spot where it was found. The Pillar was set back upright, and the earth and stone mound covering the passage and chamber was reinstated, but clearly there was much less material available than had been used originally. Some additional concrete roof supports have also been added at some point. Norman Lockyer, who in 1906 published the first systematic study of megalithic astronomy, had argued that Bryn Celli Ddu marked the summer solstice. This was ridiculed at the time, but research by Christopher Knight and Robert Lomas in 1997- 98 showed it to be true. Knight and Lomas also claimed that year-round alignments allowed the site to be used as an agricultural calendar. Steve Burrow, curator of Neolithic archaeology at Amgueddfa Cymru (National Museum of Wales), has more recently supported the case for summer solstice alignment. This alignment links Bryn Celli Ddu to a handful of other sites, including Maes Howe, Orkney and Newgrange, Ireland, both of which point to the winter solstice. It has also been suggested that a