bit bigger than a riverguessing from Willd's location, I'd reckon the river is either the Avon (as in, Stratford-upon-...), or the Severn.
It did look like that in the Street View picture, but as my personal picture shows - it is actually more of a 'waterflat'!Looks like a waterfall type thing there.
My singlespeed bike is not great on big hills! You are correct. We were far from that Yorkshire border.Due to the lack of any visible hills through the trees, I'm guessing that we're not on the yorks/lancs border?