Stonewalling is like doing a jigsaw puzzle, according to some experts in Northumberland.

‘You need to know your stones and you have to pick the right pieces from the pile. Each stone has to cover the join of the two beneath it.’ The type of stone used ? limestone, whin, sandstone ? depends on the location not the wall and is chosen to blend in with the landscape. A good day for one man would mean completing 4-5 yards, and the average height of a wall is 4 ½ – 5 feet.

Teams use a frame to get the shape right, ensuring that the wall tapers from 24 inches wide at the bottom to 14 inches at the top. Cement is used on the top of the wall to prevent cattle knocking off the stones, but the wall’s overall stability depends on the skill of the craftsmen.

Featured in Country Life’s Living National Treasures, 1997