Fascinating thread, hadn't thought about the railroad connection before but now you mention it I'm seeing it everywhere in the reports I've been reading through.
Do you think the old lines act as some kind of corridor or pathway? I know ley lines get brought up constantly on here and people roll their eyes, but abandoned rail routes do tend to cut through very old land in a fairly straight path. Could there be something to that?
Also wondering whether its the physical structure - old tunnels, cuttings, embankments creating hidden spots - or something more to do with the history of the land itself before the railways were even built.
Has anyone actually mapped out multiple sighting locations against old rail network maps? That seems like it would be worth doing properly. I'd do it myself but I'm not great with that sort of thing on a computer. Anyone with better skills than me want to have a go at it?