From the North:
Proceed along the M56 until you see signs for M53, then follow M53 until you see signs for Wrexham, Corwen and Bala. Upon hitting Bala, turn right on A4212 and follow until junction of A470. Turn right towards Porthmadog and watch for signs to Harlech at Maentrog.
From the South:
M1 or M40 north towards M6. Join the M54 going past Telford. The road becomes the A5. Go around Shrewsbury before turning west onto the A458. Follow signs for Dolgellau (you will join the A470 just before Dolgellau). Once there follow signs to Barmouth then Harlech on the A496.