Culvert, Arch And Retaining Walls, In West Face Of Embankment Over Causey Burn

The culvert, arch, and retaining walls are located in the west face of the embankment over Causey Burn and date back to 1717. They were constructed for Mr. Wortley and Colonel Liddell as part of the engineering works necessary for the Tanfield wagonway, which includes the Causey Arch at the south end of the embankment. The structure is made of coursed squared sandstone with ashlar dressings.

The retaining walls, which are approximately 80 meters long and 2 meters high, funnel towards a portal arch featuring voussoirs beneath a stepped retaining wall. The top course of the first step of the wall has a rough inscription reading '1717' along with initials that are likely C.T., though these are partly obscured by moss. The Causey Arch is noted as the first railway bridge in the world, making this structure significant as the first railway embankment and the first railway use of culverting. These works were described by Stukeley in 1725 and are recognized for their historical importance.