I looked at this last year and it did seem vaguely familiar but I couldn't quite pin down the location. Then I just came across it yesterday while I was browsing around Google maps. Felt a little silly as I had seen the long structure before.
I'd decided to get it today and coincidentally happened to met the owners while searching for another cache early this morning. They said it ought to be ok as it hadn't rained much recently. However we had a sudden downpour in the afternoon for an hour just as I was going there and it got very slippery at the GZ. After about half an hour I resorted to a PAF and WW2 guided me to correct tree. I'd rate this higher than a 3 terrain (maybe 3.5) as it can be quite dangerous when wet