This page on the Tha Engliscan Gesithas site is an interesting argument for the hills here being the ‘Woden’s Hlaew’ mentioned in Anglo Saxon documents – and thus once sacred to Woden.
Maybe it could be that people were aware of the earthworks up here and just put them down to Woden (in a kind of ‘Grim’s Ditch’ sort of way).
That’s if there’s truly any link at all of course...