A point worth noting I found out today is that the Peak District National Park Authority will not grant cache permission on their owned woodland under any circumstances. I suspect knowing them, this will echo to all their land. Very disappointing.
"Thank you for your enquiry & I’m sorry to disappoint you in this, but geocaches or anything else placed in our woodlands, however discreetly, are not welcome. Please note that there are many private landowners who may permit this sort of activity. Yours sincerely, Richard Claxon."