Harlech Beach is a long, open sweep of sand below the castle, reached by a short path from the car park near the railway crossing. It feels bigger than the town deserves, with wide views across Tremadog Bay and plenty of space even in good weather.
The dunes behind the beach are not just scenery. They are part of a protected National Nature Reserve and Site of Special Scientific Interest, and they give the castle its best low-level foreground. Come here after the castle if you want the whole Harlech picture: battlements above, marram grass at your feet, and the mountains sitting behind the town.