On the side of the B4518 – just north of the junction with the side road which leads to the nearby Pen-y-Gaer Hillfort. There is room to pull over on the verge just after the road cuttings on your right – the Hillfort is directly above these cuttings.
Be careful as although this is only a B road it is very busy.
I jumped over the gate and headed up through the field of sheep. At the top of the field was a second gate to jump over. This then leads you into the western side of the Hillfort. Much of the southern/eastern part of the site is covered in gorse and bracken.
To be honest there is not a great deal to see other than the banks and ditches on the western side – although this is more than made up for by the great views.
The Pen-y-Gaer Hillfort is easier (and safer) to access and has better remains so would be my suggestion if you only have time to visit one of these Hillforts.