Hen Castell

The Iron Age fort sits on a steep hillside near Crickhowell, commanding views across the Brecon Beacons. You're looking at serious earthworks here - a double-ringed defensive structure that's been doing its job of impressing visitors for nearly 2,500 years. Walking the perimeter takes a good hour if you're the type to stop and read the landscape properly, though determined hikers can do it in half that time.

What strikes you most is how the locals would have arranged themselves - inner ramparts, outer ditches, the whole setup designed to make life miserable for anyone thinking of attacking. The views from the top are genuinely excellent, and on a clear day you can see proper distance into the surrounding valleys. It's free to visit and there's no faffing about with opening hours since you're just turning up to a hillside.

This isn't for everyone, mind. If you're after a quick snap for Instagram, move on. But for walkers with an interest in Iron Age settlement patterns, or anyone who genuinely enjoys reading a landscape, Hen Castell delivers. The nearby Cwmdu Campsite makes a solid base for the area - less than five miles away and well-reviewed by people who've actually stayed there. You could easily combine this with walks across the Brecon Beacons proper. Bring proper boots though. The ground can be boggy and the slope is no joke.