Again, I agree with what you've said (and yes, smaller structures are most at risk in these situations) - I don't know anything about Dartmoor NPA, but it strikes me that the current fencing/cow thing in Penwith is occuring precisely because the National Trust and other landowners don't want to bother with "active conservation" and may well also be happy to keep access restricted as it makes for easier management.

It would be a terrible shame if the only way to "preserve" sites like the stone rows on Dartmoor was to put fences across the open moors to allow the introduction of stock. There must be a way of balancing the need to keep down the encroaching vegetation and also allow access to the sites for all.

The sad thing is that there are individuals in these areas who would gladly give up their weekends to clear sites if that would help keep the gorse/bracken problem at bay.

I have not been to West Penwith since November, so perhaps I'm overstating the problem there and speaking without first-hand information. However, after first going there due to reading about the sites in the pages of TMA (the book), I have visited many, many sites because of the works of Ian McNeil Cooke and Craig Weatherhill. Both of these people are deeply unhappy* with the way that things are being "managed" and I respect their opinions.

Alken

*I don't claim to have personal knowledge here, but both are actively involved in the campaign to prevent the Heath Project carrying on with the fencing, etc, so I feel pretty safe saying this.