June 22, 2006 — An ancient British tomb monument contemporary with the first phase of Stonehenge’s construction suggests one prehistoric culture built the two structures to mark the summer solstice, according to archaeologists.
The tomb is called Bryn Celli Ddu, which in Welsh translates to "the mound in a dark grove." It is located on the island of Anglesey off the northwest coast of Wales. New radiocarbon dating of postholes outside of the burial monument determined the mound is over 6,000 years old. Stonehenge dates to around 2800 B.C., but some historians think it could be much older.
According to research published in the current issue of British Archaeology and the National Museum Wales Book "The Tomb Builders in Wales: 4,000-3,000 B.C.," both Bryn Celli Ddu and Stonehenge are aligned with the summer solstice.
The heel stone at Stonehenge marks this event, while a passageway and quartz-rich stone located in the back of the burial monument lights up in a dramatic sun show.
The exterior postholes indicate a wooden structure may have preceded the current tomb monument, which consists of a stone circle surrounding a stone-lined passageway that leads to an internal chamber.
Steve Burrow, curator of Neolithic archaeology at the National Museum Wales, suspected that the tomb might mark the midsummer rising sun, so he stood in the chamber last year at dawn on the summer solstice to see what would happen.
"It’s stunning," said Burrow, who made the discoveries and led the research. "First there is a sparkle through the trees, then the sun rises out. It’s quite exhilarating."
Although Stonehenge and the mound were erected at approximately the same time, Burrow told Discovery News that the construction of the mound "reflects a much older tradition."
Stonehenge is a more complex structure. For example, it consists of two stone circles, the first of which is topped with smaller blocks. The inner circle additionally contains two horseshoe-shaped sets of stones that are set inside of each other.
Color is also a component at Stonehenge, since the outer circle is made of gray sandstone while the inner circle is comprised of blue stones. Eighty yards to the east of Stonehenge’s center rests the solstice-marking, 16-feet-tall heel stone, which was erected during the first of the monument’s three construction phases. The last phase concluded approximately 3,500 years ago.
"It’s as if the builders of Stonehenge were translating an interest in the sunrise from a centuries-old burial tradition to a new religious tradition," said Burrow. "I think (the mound) tells us something about where the builders of Stonehenge got their inspiration. Bryn Celli Ddu is the only other monument in Britain to have a midsummer sunrise alignment."
Burrow’s finding confirms speculation by scientist Norman Lockyer, who in 1906 argued that the Anglesey tomb marked the summer solstice. The new discoveries may also quell disputes over Stonehenge’s original significance.
Since the Salisbury Plain megalith also marks the winter solstice, some archaeologists have argued that winter may have been a more important time for its builders. Summer now appears to have been at the heart of many probable early rituals.
The sun's cycles aren't the only celestial event to have inspired ancient builders.
A team of scientists from The Archaeology Safaris excavation and tour group in Tewkesbury, England, recently announced that they found 27 cup marks on stones near Bryn Celli Ddu. These are circular depressions intentionally chipped out of stone.
Many archaeologists believe cup marks represent the stars and were meant to show the stellar orientation of megalithic sites.
