I was doing some aimless flying/sight-seeing, and looking down (from 16,000) saw what might be a river, or, the trench line. (in addition to height, it was quite hazy) I dropped down for a better look, and it was a river, there was a bridge (white arrow) but the odd thing about it was that the river appears to run up and over the hill.

The Dev's stated this before and if I recall correctly, said that is is a default CFS3 problem.

There is a kick arse spring at the top of the hill

I see that sort of thing often in flight sims and combat flight sims. Not a big deal for me

Yeah, CFS3 always was weakest when it came to things on the ground. And, as MudWasp said, it's no big deal, but it does bring a smile...and in 1916, we need all the smiles we can get.

Great explanation!