The strange saga of a supposedly prehistoric monument in a Scottish farmer’s field came full circle this week. Archaeologists announced two weeks ago that they’d discovered a 3,500- to 4,500-year-old stone circle standing in a farmer’s field outside the town of Alford, 40km (25 miles) west of Aberdeen. In a surprising twist this week, the circle turned out to actually be the work of the local farmer who owned the land in the 1990s.

“It is totally OK to laugh at this story. We all have!” archaeologist Neil Ackerman of Aberdeen Council Archaeology told Ars Technica in an email. “While on the surface this is a humorous story about us getting it initially wrong, it is an example of how archaeological research is carried out and that initial interpretations end up changing as new information comes along.”

If it seems too good to be true...

The ten large stones—each about a meter (3.3 feet) tall—stand in a 7.7-meter-wide circle overlooking the surrounding countryside. They certainly look like the work of the ancient Celts, somehow remarkably untouched after thousands of years. On the southwest side of the circle, one large stone lies on its side between two standing stones, a design common to stone circles in the area, known as recumbent stone circles. Archaeologists are still debating the reason for that alignment, but it’s unique to northeast Scotland and southwest Ireland.

Archaeologists know of around 90 other stone circles built this way, but most of them have been damaged or completely dismantled over the centuries. People removed the stones for other uses, leaving behind just a few stones or their settings dug into the earth. That made the Alford circle cause for great excitement when Ackerman and his colleagues arrived at the farm to survey it in November 2018. They had gotten a call from Fiona Bain, a former owner of the farm who had apparently tried for years to research the circle, with no luck. It remained on her mind after she sold the land recently, so she finally called archaeologists from the Aberdeenshire Council to see what she could find out.

It’s impossible to directly date when a stone circle was built—you can tell how old the rock is, but it’s much harder to tell when a stone was last moved. But archaeologists had excavated burials and other features of several stone circles in the region and managed to radiocarbon date bone and wood from those sites. Because the Alford circle looked very much like those other stone circles, Ackerman and his colleagues concluded that it was probably from the same period. They didn’t plan to excavate because of how expensive the process would be, how much it would damage the site, and how much it would disrupt work on the farm.

...it probably is

“The original announcement was made after a fair amount of research that led us to think at that time that it was likely to be ancient,” Ackerman told Ars Technica. “As always within archaeology, though, research continues in the background.” And even before the replica-building farmer came forward, the team had started to question the age of the stone circle. Under closer scrutiny, some details just didn’t look quite right.

The circle was a little too small, for one thing: recumbent stone circles like the one in Alford are usually at least 11m (36.1 feet) wide. A more detailed survey raised more questions about the alignment of the stones, which turned out to be just a bit off. And while recumbent stone circles were usually built atop the remains of earlier sites, including stone cairns marking the burial of cremated human remains, the Alford circle apparently had no cairn stones.

Those suspicions deepened as the archaeologists studied old land surveys, maps, and aerial photos, ranging from the 1800s to the 1940s. A thick patch of spiny shrubs called gorse made it hard to tell whether the circle was there in the 1940 aerial photos, but it was oddly absent from the 19th century Ordnance Survey maps, which are usually remarkably accurate.

“Nothing was depicted on these maps in the field, but again this is not altogether unexpected,” Ackerman told Ars Technica. “It is in a rural location and the topography of the field means if the mapping was done without actually going into the field it could easily be overlooked.”

So the team turned to a map of the large estate that once owned the land; estate maps tend to be very detailed and would likely have included something as large as a standing stone circle—but the map held no trace of the circle.

“Given the growing evidence from historic mapping, we would have probably been able to date it to having been built within the last century,” Ackerman told Ars Technica. “While we may not have figured out exactly when it was built, it would have probably ended up being classified as a more recent replica,” he said, although the archaeologists generally agree that it was a very good replica.

Everyone needs a hobby

A phone call from a local farmer finally confirmed the team’s growing suspicions. The former landowner had seen the press coverage about the “ancient” stone circle, recognized their own handiwork, and decided to call Adam Welfare of Historic Environment Scotland and clear things up. But it hadn’t been a hoax or a play for attention—just a landscaping project by a local history enthusiast.

“The farmer who built it did so as a replica for a garden feature for their own enjoyment,” Ackerman told Ars Technica. “There was certainly no malice intended in trying to fool anyone—they just did a particularly good job!”

In fact, the amount of detail the farmer got right was pretty impressive, especially for a hobby project, say the archaeologists.

The land has changed hands a few times since the 1990s, and evidently the original local history enthusiast forgot to mention the work to the next set of buyers, so it didn’t take long for its origins to be forgotten.

But the story isn’t quite that simple. There may once have actually been a stone circle near the modern replica. Several local people told the archaeologists that they remembered walking past the field and seeing standing stones there as early as the 1930s, although others said they never had. Ackerman told Ars that other stone circles once stood nearby, including one demolished in the 1950s. He thinks it’s more likely that the elderly local resident actually saw a pile of stones cleared from a plowed field—perhaps the same stones later used to build the replica in the 1990s.

The story is a good example of how new information can force scientists to reconsider their initial conclusions. “I also think it is important in all walks of life to be open to new information that can question your ideas and hold your hands up to say when you got it wrong,” Ackerman told Ars. He says he and his team don’t regret their initial announcement.

"I am personally of the opinion that saying what you think you have is very important even if that does mean you later have to correct yourself. There are plenty of examples where archaeological fieldwork is never fully published, which is a much greater issue than publishing and later correcting," he told Ars Technica. "Archaeology, and the sciences more broadly, can be guilty for various reasons of shouting about perceived successes and whispering about perceived failure. However if those outside of the field of study are not given a true picture of what actually goes on in these kinds of situations it is easy for misunderstanding to happen."