It's a little to the West, at Rudge, called The Walls. (Fork right behind The Royal Oak on the Bridgnorth Road and take a footpath to the right after a hundred yards. Very pretty, it's been a favourite walk of mine for 50 yrs).
I always understood that it was simply "R*man", but it's mentioned here...
http://www.roman-britain.org/tribes/cornovii.htm
... as being Pre-Roman Cornovian, which is what he meant by the term Native Fortress I presume.
(NB-It's called Chesterton Walls, not to be confused with another Chesterton of that tribe that's mentioned near Newcastle u Lyme).
I'd be interested to know what you find out.