Why not hire a skip and go down and clear away the mess?

Make a big deal about it to the press - "we have lost patience it is obvious that care is a lip service only round here" while you are on you can also say that we even think the hill is an ancient monument, say we approached EH about it and they did not seem interested etc.

At the same time put in a lottery grant application for a range of non intrusive investigations to take place and for some signage.

I take it we have asked EH if they know anything about it?