Looking at the bailey ditch.The bailey rampart comes from the lhs of image,behind the tree.
see http://www.castleuk.net/castle_lists_midlands/166/wymondley.htm
see http://www.british-history.ac.uk/report.aspx?compid=43600
see http://www.hertsdirect.org/libsleisure/heritage1/archaeology/moreaboutarch/archsites/wymondleymotte/
see http://www.castlefacts.info/castledetails/castleDetails3.aspx?uin=11566