Weird Green Thing
It's a sorta onion-shaped thing on a stalk that sits up on the ridgeside and no-one knows what's it's for.
But I found out today when I walked up there it's a reservoir. Or maybe it's and alien thingy and it just says reservoir on the sign.
(You know I'm kidding about the alien thingy, right? Don't be emailing me and telling me how you got probed. Unless you got pictures of the probing.)