A second multi from the viaduct, but this one will require a lot more effort to get to the final stage of. It's not that far as the crow flies, but I'm making the presumption that you're not a corvid if you're geocaching. There are lots of options of how to get to gz, and it is possible to park a bit closer, but it will still require a reasonable walk in decent shoes/boots.
You will need to visit 2 waypoints, close together.
At the posted coordinates, you will see a bridge number sign.
A: Bridge number, 3rd digit - 2nd digit
B: Single line built in 187B
C: Second line built in 187C
At the second waypoint:
D: The spectacular view from this viaduct spans some 3D0 million years of the history of our planet
E: There are 1E information 'bubbles' (with a number in a circle)
F: Limestone was quarried at meldon pool from the 1F90s
G: The short lived glassworks was here in the 1G20s
H: Meldon dam holds back up to 3H0 million litres of water
Cache at N50 4A.BCD W004 0E.FGH
Checksum, A-H = 38