....... running over the bridge uphill from left to right.
Uphill, L to R? It looks the other way in the photo. Optical illusion? It also looks as steep a gradient as a normal railway can cope with.
Hilly, wooded perhaps and old railway lines? Sort of describes the Forest of Dean?
It was a 1 in 60 gradient. I agree that it looks the other way round, but trains going up hill passed from left to right over this bridge. Despite appearances, it's a suburban location.
Are we in the Mangotsfield area?
Not really. The line was part of the
GWR▸ network. According to Google, it's about 12.3km from Mangotsfield Station by bicycle; you could cover a decent chunk of the route on off-road paths along former railway lines...