This is the 1808 aqueduct built by Telford for the Ardrossan Canal over the river; the canal became defunct and a railway line was laid along its route at the end of the nineteenth century.
The railway line is still in use, and therefore this bridge is stated to be the oldest bridge in the world still carrying an active railway.
Photograph taken 7 January 2015 from the SE quadrant; the river is the White Water of Cart, running about east to west here, and the railway is "to Glasgow" away from the camera.
Licensing
I, the copyright holder of this work, hereby publish it under the following license:
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.