Fans of the 1984 heavy metal mockumentary “This Is Spinal Tap” will remember the scene in which the band commissioned a set that is a replica of Stonehenge, the Neolithic ruin in Wiltshire, England. Unfortunately, a careless set of measurements results in the musicians playing next to a model that is not just 18 inches high, but 18 inches high. This is a mistake that is shown on the tour and is impressively amplified by the dancing gnomes who make the prop appear larger.

Thirty-seven years later, it turns out that the film’s boulder gag contains a pebble of historical truth. On Friday, a team of archaeologists reported in Antiquity magazine that they discovered a stone circle in Pembrokeshire, Wales, which they believe had been mined, moved 175 miles to Salisbury Plain and reassembled as Stonehenge.

Mike Parker Pearson, a professor at University College London who led the study, said the stones may have been transported to the area as part of a larger movement of people. “Stonehenge is a used monument,” he said sardonically. The study will be featured in a BBC documentary entitled “Stonehenge: The Lost Circle Revealed” which will air in the UK on Friday night.

Stonehenge was founded in phases from about 3,000 to 1,500 BC. Built starting with a circular moat and bank along with 56 Aubrey holes, a ring of chalk pits that encircled a stone circle. An excavation of a pit in 2008 under the direction of Dr. Parker Pearson revealed it contained a bluestone post, so named because of its bluish-gray hue. The outer ring of these igneous standing stones, each about ten feet high, was erected centuries before it was thought that larger slabs of sandstone known as sarsens came from West Woods, 15 miles away on the southern edge of the Marlborough Downs.

The geologist Herbert Thomas found in 1923 that the dolerite used to build Stonehenge came from an outcrop in the Preseli Hills in west Wales. In 2011, Dr. Parker Pearson found two megalithic quarries in the area and began searching nearby for ritual structures that may have supplied the bluestones and blueprint. Although several circular monuments have been surveyed and excavated, none have been found to be Neolithic. In an interview, Dr. Parker Pearson, his investigators had a “terrible time” to find evidence of a Proto-Stonehenge.

The researchers were about to give up when they returned to a place called Waun Mawn, where a handful of fallen bluestones appeared to be placed in an arch. “The arrangement was first made a century ago,” said Dr. Parker Pearson. “The theory of early archaeologists that it could be a circle has been largely discarded or simply ignored.”

In 2011, his own magnetometer and earth resistance surveys had found no geophysical anomalies that could provide evidence of a circle or monument. “We came to the conclusion that there couldn’t be anything there because the instruments weren’t showing us anything,” recalled Dr. Parker Pearson. “A serious mistake.”

In the summer of 2017, archaeologists dug trenches from serving stones at both ends of the arch and discovered two holes in each of which stones were once held. When further earth resistance, ground penetrating radar, and electromagnetic induction studies failed, the team made a literal final effort beyond the arch and uncovered four prominent pedestal-shaped pits from which standing monoliths had been removed.

From the positions of the empty plinths and the fallen bluestones, the researchers extrapolated a circle with a diameter of about 30 meters – the same diameter as the ditch that originally surrounded Stonehenge. Dr. Parker Pearson, on fire with boyish glee, noted that Waun Mawn and Stonehenge are the only two Neolithic monuments in Britain that meet these specifications. To his further delight, the entrance to both circles faced the summer solstice sunrise.

The team was able to determine when the sediment in the plinth holes was last exposed to light. The study suggested that Waun Mawn is the oldest known stone circle in Britain and dates back to around 3,400 BC. Dated. The circle was established just before Stonehenge was built in 3,000 BC. Dismantled

Dr. Parker Pearson hypothesized that the six ghost holes and four surviving standing stones were part of a larger circle of 30 to 50 columns, albeit more randomly distributed than the original bluestone grouping in Stonehenge. These four stones are roughly the same size and size as the 43 bluestones that remain in Stonehenge and are exactly the same type of rock as three of them. One of the Stonehenge bluestones has an unusual cross-section, the pentagonal shape of which matches one of the gaps at Waun Mawn.

“It could have been in that hole,” said Dr. Parker Pearson. “The evidence is not categorical, but it is very suggestive.”

When asked why the Waun Mawn stones were brought to Salisbury, he referred to his colleague, an archaeologist from Madagascar named Ramilisonina, who developed a new interpretation of the ritual landscape around Stonehenge: the megaliths were used to represent the ancestors and more or less to keep memories alive for the ages.

“The quarrying of Waun Mawn and the ascent of Stonehenge may have been part of a larger hike towards an Axis Mundi where earth and sky are in harmony,” said Dr. Parker Pearson. These old people, he speculated, “may have taken their monuments with them as signs of their ancestral identities that they needed to take root in a new Jerusalem.”

How were the megaliths transported from South Wales to Salisbury? Dr. Parker Pearson questions the once popular theory that they came by sea. “Our work really did speak a bit,” he said. “The dominant sources of bluestones are the quarries on the northern slopes of the mountains, and it is unlikely that they were brought up the steep northern edge before being carried down the southern slopes into the valley.”

He prefers a land route over which the massive stones, each weighing up to four tons, can be pulled by up to 400 people onto rows of poles and wooden sleds. “It would have been like going to the moon,” he said, “but the Neolithic equivalent.”

Megan Specia contributed to the coverage.