Craig y Dinas is an Iron Age Hillfort situated on an isolated rock at 350m above sea level in a wide upland valley cradled by the mountains of Moelfre, Diffwys and Llawlech. It is easy to pass by with barely a glance when following the ancient tracks which criss-cross the area, but is well worth a visit, retaining many of its original features including remains of stone ramparts and Iron Age roundhouses. It also boasts wonderful views of the sea and the mountains. Our walk heads up on the track from Cors y Gedol Hall, soon cutting off onto open country towards the hillfort. There is a slight scramble to get into the fort itself but any who prefer to miss this out can return to the track and continue to Pont Scethin pack-horse bridge where we will reassemble and take a break. We then turn towards to the peaceful lake of Llyn Erddyn, nestling under the impressive Llawlech cliffs, continuing to Pont Fadog and back to the start.