How awful about the dew pond. It is strange people do stuff like that when you'd think their families probably have been in the area for generations, and you'd think they'd value the historicness of it. Or is it 'familiarity breeds contempt'. The barbed wire though, that sounds like contempt for walkers, but why? What I came across this weekend wasn't so obvious, it was more 'remove all signs and dare them to walk across my yard' (it put me off anyway). In your case, would you not be completely justified in snipping the wire - it's a right of way?