Hi, just a quick one before you go..... I live quite near to Rowen which is oft overlooked and good for a rummage along an old roman road, there is the Maen y Bardd burial chamber and a number of standing stones...
more info here:
http://www.walesdirectory.co.uk/his/bury/bwlch.htm
http://www.walesdirectory.co.uk/his/bury/bardd.htm
http://snowdonian-walking.co.uk/walking%20in%20North%20Wales%20rowen.htm
It is an extremely steep long walk to the tops above Rowen - it is possible to drive up to the top and park near the youth hostel.
Happy Hunting!