2 Long barrows not far away:
http://www.magic.gov.uk/rsm/27891.pdf

Cool site that - been playing around with it this afternoon.
Sadly, those two sites aren't the ones I'm looking for, but I'm definitley going to check them out next time I'm up there! :o)

Looks like the field I'm talking about isn't scheduled. It's the field in the middle of http://www.multimap.com/map/photo.cgi?client=public&X=508000&Y=374500&scale=10000&width=500&height=300&gride=508015&gridn=374120&lang=&db=pc&coordsys=gb which seems to have defined structure in that photo. Maybe it's something more recent - I'm not sure. Never been ploughed as long as I can remember...

Any more ideas appreciated! ;o)