I visited this site about two years ago whilst visiting nearby Tintern Abbey (CADW).
The site is easy enough to find – take the first turning on the left driving north through Woodcroft. The lane is quite narrow but there are places to park on the left with good views across the river Wye. The lane runs right next to the western edge of the hillfort and there is a fence surrounding the field. When I visited sheep were grazing in the centre of the Hillfort. I had the baby with me at the time so I settled for a view from the lane. To be honest there wasn't much to see – the centre is a flat grass field and the other 3 sides of the Hillfort are covered with trees.