Well there has been an awful lot of discussion around on this subject of Our Sacred Land and I see John Vidal has also said something in the Guardian this morning.....
http://www.guardian.co.uk/uk/2011/sep/06/national-trust-planning-reforms
about the National Trust's epetition launch against the planning reforms.
Not an organisation which you might see as predominantly prehistoric but at least it does a lot for protection of heritage...