Visited Winter 1999 (I think): The climb up to Dinas isn’t quite as bad as it looks, but you’d be hard pressed to get a pushchair up there. Approaching from the south you can park at the gate just to the north of the bridge (SN741827) and there’s a public footpath that goes east, then north, passing to the east of the hillfort. Obviously there’s no point in sticking to this path because you’ll miss the views to the west, and any chance of identifying the ramparts of the fort itself.
Up at the top the views are spectacular, especially to the west and east (towards Pumlumon Fawr). The climb is worth it just for the feeling of splendid isolation, and knowing that you’re slap bang in the middle of an excellent cluster of upland Bronze Age sites.