Dinas hillfort is a strongly sited hillfort at 385m above sea level, which occupies a narrow ridge with very steep slopes on the west and east sides. The hillfort overlooks the upper Rheidol on the east side, and the tributary at the foot of the west side of the ridge is also deeply cut. Access to the summit is easiest from the south side, where one ascends from the more gradual terrain and meadow land flanking the Rheidol at Ponterwyd.

The hillfort is pear-shaped, 107m N/S by 51m E/W. Hogg (Cardiganshire County History 1994, 270) described the rampart as `'a stony bank, about 5.5m wide and just over a metre high externally.'. It appears to have been quarried from broad internal quarry ditches on the north and south sides. On the west the rampart partly incorporates the outcropping rock on the summit. The original entrance, an unelaborated gap, is centrally placed in the rampart on the south side and commands panoramic views to the south.

Hogg (ibid.) records one certain house platform and three possible; the certain platform lies towards the centre of the fort, but there is a second on the south side overlooking the main gate, and possibly two others on the north side. However, the northern part of the interior has been confused by digging, possibly from mining work in more recent decades. An internal subdivision, a low bank and ditch, cuts across the centre of the fort and may be an original feature. Visited on 9th January 2000.

A possible cist burial has been reported from the interior (?) of the enclosure (Nprn402234).

A platform, thought to represent a hut circle, is known some 450m to the south.

T Driver, RCAHMW, 15 September 2004.