PICTURED from the air, the scale of work being undertaken on the A465 between Gilwern and Brynmawr is brought into perspective.

The old notorious three-lane road, in place since the 1960s, is disappearing to be replaced by dual carriageways.

The new concrete arch bridge at Gilwern is the largest of its type in the world; 6,200 metres of retaining walls have been built to date and more than 4,000 trees have been planted.

Dozens of diversions to water mains, gas mains, phone lines and electricity supplies have been completed; including a water main that required a new 1.5m wide, 100m long tunnel at a depth of 20m below the surface.

The builders also had to deal with a number of old mine workings uncovered near the Brynmawr junction. The project is due for completion in mid 2019.