Tregarth Park

The Afon Ogwen cuts through a proper gorge here, and Tregarth Park is where you go to see it without paying a penny. It's a nature reserve just outside Bangor, so close you could almost cycle there from the town centre, and the river runs through woodland thick enough that you genuinely feel miles from anywhere.

Walkers will get the most from this one. The paths follow the water, and depending on how keen you are, you can spend anywhere from forty minutes pottering about to a couple of hours if you fancy exploring further up the valley. The gorge itself is the main draw - steep sides, rushing water, trees overhead. On a grey Welsh day it's atmospheric rather than postcard-pretty, but that's rather the point.

It's free, open all hours in the way nature reserves are, and genuinely worth the detour if you're staying at Ogwen Bank Caravan and Lodge Park just two miles away - barely five minutes' drive. There's limited formal infrastructure, so come prepared for muddy boots and actual terrain rather than manicured walks. Not a spot for young children who need hand-holding, but anyone aged eight upwards with reasonable legs will manage fine. The riverside setting makes it a solid complement to a park-based holiday in the area, giving you at least one proper woodland expedition without leaving Gwynedd. Summer's pleasant enough, but October onwards when the trees colour up is genuinely lovely.