Caer Drewyn Hillfort dates to the Iron Age 700BC - 50AD. It has commanding views and shows evidence of having been occupied over different periods with the remains of a number of defended closures, banks, stone ramparts, huts and ditches. The site is west on the A5 from Llangollen to Corwen where the B5437 takes you to a junction of the A5104 where a right turn leads to a signposted footpath to the Fort.
Link and Image: Llangollen website