Rising behind Barmouth, rocky Dinas Oleu (258m) made history in 1895 by becoming the first property ever bequeathed to the National Trust, kick-starting a movement dedicated to preserving Britain's best landscapes and buildings. A network of trails covers the 4.5 gorse-covered acres of the 'Fortess of Light', including the popular Panorama Walk (signposted from the A496 on the eastern edge of town), which has the best views of Mawddach Estuary.
Otherwise, scramble up any one of several alleys running off Barmouth's High St, where you'll find the town gets more and more vertical, with better and better views, until the old houses are nearly on top of one another.