Cast your mind back to pictures in school books about the building of the ancient pyramids and you probably remember images of hundreds of workers in loincloths heaving massive stones up ramps.
Peter James and his team have been restoring the Egyptian pyramids for 18 years, with his company Cintec working deep inside the iconic structures.
He began to question how they were really built up to 4,000 years ago. He says the traditional view, that hundreds of workers manoeuvred two million stone blocks, laying one every three minutes, is impossible.
He says the pyramids are so tall that the ramps would have needed to be at least a quarter of a mile long or they would be too steep to move the blocks along. He adds that had that happened, there would still be signs that the ramps had been there.
Instead, Mr James says, from what he has seen working deep inside the pyramids, he believes they were built from the inside out, with large stones on the outside and small material inside - a bit like a modern builder would construct a stone wall.
Mr James is managing director of Cintec International based in Newport. He employs 50 people and works across the world but has particularly been involved strengthening and restoring ancient monuments in Iran, Iraq and the Sahara, as well as Wales and England, where he's strengthened walls in Buckingham Palace and Windsor Castle.
One technique he's invented - and patented - is to drill into the ancient structures and take out a core of stone, almost like an apple core, and then use something he's developed a bit like a syringe to squeeze in thin concrete so no air is trapped.
Inside the Step pyramid in Egypt, they discovered that a massive tonnage of small stones was being held up by only the trunk of a palm tree thousands of years old. Traditional tubular props could damage a pyramid wall so, together, the Cintec team invented a new way of supporting the pyramid from inside.
They designed large airbags, one and a half metres high and a metre in diameter which they used, 11 at a time, inflated on site inside the pyramids. They are made in Cintec's factory in Cwmbran, strong plastic welded together with a very particular design of webbing inside so that the structure remains stable. They are fully inflated within the pyramid and in effect form a cushion.
Peter James says: "It was described to me that we were kissing the stones and stopping many tonnes of stones from falling on our heads."
His company is still working in Egypt and on many other historic sites around the world. He is now preparing to tell Egyptian archaeologists about his discovery and how he is challenging thinking accepted over generations about the way the pyramids were built.