Another site I visited last year whilst staying in Bala - another CADW site! I had a bit of difficulty finding the cross through the maze of country lanes despite having an O/S map. Eventually I asked a chap out walking his dog who pointed me in the right direction. The only advice I can give is that it is situated in a field at the crossroads of several lanes. It is not visible from the lane but there is a gate and once you get into the field it is easily seen just a short walk away. The carvings are fantastic and although I have seen several such crosses this is easily the most impressive in both size and patterns on all four sides of the cross. (The one near Carew Castle in South Wales is pretty good too).
Well worth the effort to find.