In addition to enjoying cycling, I'm also, I confess, a bit of a ferroequinologist. (Train Spotter). And of course, part of the enjoyment of cycling is looking at the landscape, seeing how everything fits together, and how it might have been formed and used.
I reckon the bridge on the approach to Collieston is a relic from the old Great North of Scotland Railway Boddam branch, which left the Aberdeen to Peterhead line at Ellon. The branch was constructed in the 19th century, to Boddam via Cruden Bay, in an attempt to attract tourists to the coastal scenery, planned golf courses etc. A large hotel was built at Cruden Bay, but the venture was a commercial failure - passenger traffic stopped in 1932 I think, the branch closed altogether in 1945 - much earlier than most closures. The Peterhead line is also now closed.
Surprising perhaps that the bridge has lasted so long. Maybe now used for farm / livestock access?
Not much to do with Thorn bikes, I'm afraid, but it is to do with the pleasures of seeing from a bike.
I'll stop now.
Lewis