1. A large multi-vallate hillfort on a very prominent hilltop. The ramparts consist of outer banks and inner ditches, the latter quarried for the former. 3 ramparts to E, NE and N; 2 ramparts to NW; 1 rampart to SW, S and SE. At least 2 entrances to E side. A later field boundary (nprn 500565) runs up to W side, now a fence. There are a large number of sites, including hut platforms inside the hillfort (NPRN 500532-500549).
W B Horton, Hayman and Horton, 28/09/2007.

2. Penycloddiau hillfort is a great 18.9ha earthwork fortress which crowns a mountain rising from the Vale of Clwyd. It is an irregular enclosure, roughly 794m north-west to south-east by 134-332m, occupying the southern part of the summit ridge. The ramparts run along the top of the steepest slopes, which fall away precipitously on the south-west and the southern part of the east sides, where there is only a single rampart and ditch, sometimes with a counterscarp bank. The ramparts are doubled where the slopes are gentler and the original in-turned entrances open onto relatively gentle slopes beyond the north-east face and the southern end. At the north-west end the circuit cuts across the generally level ridge summit and here there are up to four ramparts. An internal quarry ditch can be seen all around the circuit.

The interior is irregular, the ground generally falling away from the summit at the north-west end. An occasional pond lies in a small valley or saddle. A number of building platforms have been observed following bracken burning in 1962 and 2003 - the latter event documented from the air for RCAHMW - and a new ground survey was carried out in 2006 for Clwyd Powys Archaeological Trust.
This is a later Prehistoric type hillfort and is likely to have been active in the Iron Age and into the Roman period. The ramparts would have been crowned by elaborate timber breastworks and the interior would have crowded with great thatched roundhouses. The fortress would have been a place of display, ritual and ceremony.

Source: Forde-Johnston in Archaeologia Cambrensis 114 (1965), 163-9

John Wiles, RCAHMW, 03.01.2008.

3. The hillfort is the focus for new excavations by Richard Mason and Rachel Pope led by University of Liverpool in 2012-2013.
T. Driver, RCAHMW