Mae datblygiad yr A465 yn un o brosiectau seilwaith mwyaf Cymru. Mae Rhan 2, rhwng Gilwern a Brynmawr, yn golygu lledu Ceunant Clydach sy'n safle hynod serth ac amgylcheddol sensitif.
The A465 development is one of Wales’ biggest infrastructure projects. Section 2, between Gilwern and Brynmawr, involves the widening of the steep sided and environmentally sensitive Clydach Gorge.