A Giant Pyramid Appeared Over Pentyrch

At around 2:40 on the morning of February 26, 2016, Caz Clarke was watching the sky near her home in Pentyrch, a village outside Cardiff in South Wales. There had been unusual aircraft activity over the area for days, and she wanted to see what was happening.

Suddenly, a red light appeared above the fields. More lights followed, and as Clarke watched, she began to realize they weren’t moving like separate aircraft.

They appeared to mark the edges of something enormous.

Something Was Happening Over the Village

Clarke had already noticed unfamiliar aircraft flying over Pentyrch earlier that week. She described small planes circling the area, sometimes flying unusually low, and believed they were watching something on the ground.

On the evening of February 25, she reported seeing a larger military aircraft circling overhead. She identified it as an E-3 Sentry, a surveillance aircraft recognizable by the large radar dome mounted above its body.

The activity was unusual enough to keep her watching. And when the red lights appeared in the early hours of the following morning, she was outside with a clear view across the nearby fields.

Six Red Lights and an Enormous Shape

According to Clarke, approximately six red, oval-shaped lights appeared to form the outline of a huge pyramid. Rather than moving independently, the lights seemed to hold their positions around a single object.

The formation was so large that Clarke struggled to judge its size. She described something far bigger than an ordinary aircraft, hanging over the countryside with its illuminated edges visible against the darkness.

As she watched, the enormous shape appeared to tilt and rotate slowly. It began moving lower toward the trees, with the red lights remaining visible as the object changed position.

Clarke also described smaller lights moving around the formation. Their movements were different from the slow, deliberate motion of the larger object, giving her the impression that several things were happening at once.

She said the experience was unlike anything she had seen before. Despite the extraordinary size of the object, she couldn’t identify the familiar engine noise she would have expected from an aircraft that large.

A Green Object Suddenly Shot Away

The encounter became even stranger when Clarke reportedly saw a bright green object emerge from the larger formation. According to her account, the smaller object accelerated away toward the northwest, in the direction of Llantrisant. It moved rapidly across the sky and appeared to flash brightly as it increased its distance.

Military aircraft were also moving through the area. Clarke believed some of them changed direction in response to the green object and began following it.

Meanwhile, the enormous pyramid appeared to continue its descent toward the woodland. Clarke described its movement as slow and controlled, with the red lights still marking its shape as it approached the trees.

At one point, she said she saw fiery-looking forms extending downward from the object. She compared them to thick fingers, reaching beneath the enormous structure.

Clarke tried to use her phone during the encounter but later said it wasn’t working properly. The experience left her with a remarkable story and a determination to find out what had been happening above her village.

Other People Saw Strange Lights

Clarke wasn’t the only person reporting unusual activity around Pentyrch that night. Another resident, Mike Henbury, described seeing a large, pulsating red light while walking his dog. He reportedly watched additional lights appear, eventually forming what looked like a triangular arrangement.

His description differed from Clarke’s in several respects, but both accounts involved unusual red lights over the area during the same period. Residents also reported loud bangs and low-flying helicopters. Some described the sounds as explosions, while others noticed aircraft continuing to operate long after the main sightings had ended.

The reports attracted the attention of UFO investigators, but the most interesting development came when Clarke began looking into the military activity.

The Military Really Was There

The first major discovery was that an organized military exercise had been taking place around Llantrisant that night. Official aviation notices identified an operation called Exercise Chameleon. One notice, numbered H0757/16, authorized up to seven military helicopters to operate without their normal navigation lights within five nautical miles of Llantrisant.

The permission ran from 9 p.m. on February 25 until 7 a.m. the following morning, covering the period of Clarke’s reported encounter.

A second notice authorized nighttime parachute operations over a larger area. That activity was scheduled between shortly after midnight and 4 a.m., with the permitted airspace reaching as high as 18,000 feet.

These were substantial operations taking place over the same part of South Wales. Helicopters could be moving through the darkness without their usual lights, while other military aircraft supported the exercise.

Clarke knew military aircraft were operating nearby. What interested her was whether the exercise explained everything she had witnessed or whether the aircraft had been involved in something else.

The Search for Answers

Clarke began working with UFO investigator Gari Jones to reconstruct the events of that night. Together, they gathered witness accounts, examined aircraft activity and submitted Freedom of Information requests seeking further details about Exercise Chameleon.

Some responses provided information about the operation, while other requests encountered restrictions on releasing defence-related material. Clarke and Jones became increasingly interested in what the available records could reveal about the movements of military aircraft.

Their investigation eventually grew into a book, The Pentyrch Incident: The Greatest UFO Cover-Up of Modern Times, published in 2021. The case also attracted documentary producers and television researchers, bringing Clarke’s account to audiences far beyond Wales.

Clarke continued investigating for years afterward, examining the surrounding countryside and speaking with people who remembered the unusual activity. She has remained convinced that the giant object she witnessed was something extraordinary.

By 2026, the case had been investigated for a decade, but Clarke was still pursuing new information. She believed additional witnesses had important evidence that had never become public.

Clarke has said that other people took pictures during the encounter.

Those pictures have yet to be released.