Apparently, the site I mentioned in my previous post was found by a couple of metal detectorists who were actually looking for evidence of a castle local legend says was in the woods. They got to the site and their detectors went nuts, beeping no matter where they were pointed. The pair dug up three items -- a ring of some sort, the metal tip of the ammunition from the sort of catapult known as a scorpio, and a horseshoe -- and posted pictures on a hobby archaeologist forum, not really knowing what they had. Someone on the forum identified the horseshoe and commented that it couldn't possibly have come from where they live. So they immediately contacted the county archaeology office. I won't know any more until probably Tuesday, but I'll post it when I find out.