A builder from a Welsh town has said he was “taken aback” when he spotted what he assumed was “some sort of a UFO” at the summit of a hill.

Craig Muir, who is in his 30s, came across the alien structure, which actually turned out to be a shiny, silver monolith – a large single upright block of stone – during his regular hike up Hay Bluff, in Powys, Wales, in the morning.

“When I first saw it, I was a bit taken aback as it looked like some sort of a UFO,” Mr Muir, who lives in Hay-on-Wye, told the PA news agency.

Man standing next to monolith
Mr Muir captured the monolith via photos and videos (Craig Muir/PA)

“It seemed like a very fine metallic almost like a surgical steel.

“The steel structure was almost 10 feet long and looked perfectly levelled and steady, despite the weather being windy.”

Since there is no way to drive up to the top of the hill, Mr Muir suggested it could have been taken by a group of people or dropped off by the helicopter on its spot.

“It didn’t seem like it was chucked in there, instead it has been accurately put in the ground,” he said.

The monolith was discovered by Mr Muir on Tuesday morning (Craig Muir/PA)

“However, there were no obvious tracks around it and one would think that there would be a lot of mess around it, but there wasn’t.”This is not the first sighting of the mystery monolith as it was previously seen across the UK and Europe in recent years.

Social media users including TikTokers and Instagrammers have previously captured the giant structure in the Isle of Wight, the Merry Maidens stone circle in Cornwall and a few isolated parts of Europe.