When I was there in spring I was lucky to hook up with the venerable Mr Quamm for some local hints. Well, I spent a week camped around the peninsula near Santiago where the main town is Muros. I spent a whole day with their nearest equivalent of an OS map, and found not one of the 8 marked rocks I looked for. Annexus scoffed and came over the next day with his car, and we went back looking for them - and again, found nothing.

Just a warning!

There's one that's signposted from a road near Muros called Laxas das Rodas which is relatively easy to find:

http://www.flickr.com/photos/gyrus/128801236/

There's also plenty more "hotspots" further south from Santiago that I gather are signposted, but I didn't make it there.

Just before I left, Annexus got chatting to the guy who runs the campsite at Ancoradoiro (past Mount Louro from Muros), and it turns out he knew the local rock art quite well. His tip (which I had to put under my hat for "next time") was to contact the local council. Apparently they're finding new stuff along that coast constantly, and he said they'd probably be keen to show keen "amateurs" as well as pro researchers around. Worth a try. As ever, speaking Spanish (or even better Galego!) would be a boon.

Happy hunting!