Drought Reveals Giant, 4,500-Year-Old Irish Henge

The circular structure in the Boyne Valley was discovered by drone photographers searching for signs of hidden Neolithic sites

Ireland Henge
Anthony Murphy

The Emerald Isle has not been so green as of late; Ireland is currently undergoing a historic drought, with some areas of the normally damp island experiencing the least amount of rain in some 160 years. It’s a sobering look into the future, since climate change is expected to hit Ireland particularly hard. But there is one positive to the dry weather. As Daniel Victor at The New York Times reports, a wilting agriculture field outside Dublin has revealed the remains of an undiscovered 4,500-year-old henge.

Evidence of the prehistoric earthwork was first observed by Anthony Murphy, who runs the website Mythical Ireland. Since the heatwave and drought have been revealing crop marks of ancient castles and Iron Age forts in Wales and England in recent weeks, Murphy decided to fly his drone over the Boyne Valley to see if anything new was showing up in his area.

Murphy was shocked when the drone revealed the outline of a circle stretching almost 500 feet in diameter in a field he’d flown over many times before. He shouted to his friend, photographer Ken Williams, who was also flying his drone nearby.

“We knew fairly quickly that what we were seeing was something very special. And huge,” Murphy recounts in a blog post. He sent on their images to archaeologists who confirmed that indeed, the drone pilots had found the footprint of an unknown ancient henge, which could be up to 4,500 years old.

An unusually high number of henges and ancient sites have been found over the decades along the River Boyne; together, they make up the Brú na Bóinne Unesco World Heritage site. But the size and layout of the new henge, located close to the valley’s 5,000-year-old Newgrange monument, makes it an important find.

“This is internationally significant and we now need to figure out what it means,” archaeologist Steve Davis of University College Dublin tells Barra Best at the BBC. “[I]t has some characteristics that we've never seen before. For example, the very odd double ditch sections that make up its circumference.”

So why do these ancient structures stand out during times of drought? The henges are actually a series of concentric circles created by placing large posts in the ground. When the henge fell out of disuse or was burned down, the underground portions of the posts rotted away, changing the composition of the soil in the posthole, causing it to retain more moisture. During a drought, while the surrounding crops yellow, the plants over the post holes have a slight advantage. “The weather is 95 percent responsible for this find,” Murphy tells Best. “The flying of the drone, knowledge of the area, and fluke make up the rest in this discovery.”

Victor reports Ireland’s National Monuments Service will survey and study the site, though the newly discovered henge is on private property and there are no immediate plans for an excavation.

Maybe not poking around the henge is for the best. After all, there's a mythical story floating around about the space where the new henge was found. According to Irish legend, once upon a time, an ancient drought was said to have struck the area, which in mythology was said to be located under water in a "magical sea" called the Muirthemne. As Murphy explains on Facebook, "There was a huge sea turtle or monster in the sea" called the Mata, which lived in the water, until, "[t]he Dagda (sun god) came along and made the water recede, and the monster receded with the water....."

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