Tomen Castell

A grassy mound rising from the valley floor near Blaenau Ffestiniog - that's Tomen Castell, and it's properly atmospheric once you realise what you're looking at. This isn't a castle with towers or walls. Instead, you're standing on the remains of a Norman motte-and-bailey, the sort of fortification that dotted Wales in the 11th and 12th centuries when the English were still trying to make the Welsh behave themselves.

The walk up is straightforward enough, maybe ten minutes from the car park, and the views across the Ffestiniog valley are genuinely worth the climb. On a clear day you can see right across the slate country. Bring a camera if you care about that sort of thing.

It's the kind of place that appeals most to walkers and history types rather than families with small children - there's no playground, no café, just the mound itself and the story it tells. You can spend half an hour here easily, longer if you're keen on Norman fortifications and want to photograph it from every angle. Free to visit, naturally.

If you're based at Llechwedd Glamping or Llyn Gwynant Campsite, this is a decent leg-stretcher during a slate-mining holiday in the area. It pairs well with a visit to Llechwedd Slate Caverns just down the road - you get your bit of medieval history and your bit of industrial heritage in one afternoon. Don't expect crowds. You probably won't see anyone else up there.