This apparently defensive structure or barrier which is quite distinct from the major field system and enclosures to its immediate SE., cuts off the isthmus of St Davids Head from just above Porth Melgan in the S to Porth Llong in the N. It consists now of a broad band of piled stones and boulders little more than a metre high, but as much as 3m wide in places, and not less than 1.5m - 2m wide overall. Where possible, especially the northern third, the line seems to follow and reinforce a natural scarp. The wall is in two sections divided by a naturally defensive outcrop. The southern two thirds is less well preserved and presents a less spectacular impression of strength than the northern section - being now rather disguised by vegetation. The northern section by contrast is visible from some distance, being built on top of a slight rise or scarp. This part of the wall has also retained what might be called associated features - at the centre are two gaps each about 2.75m wide, that at the N is reckoned to be the original gap (Grimes annotated plan) or entrance, and it certainly looks the more deliberate construction than the gap to its S which has more the appearance of being driven through the wall at a recent date. The S gap carries the track which leads to the Coast Guard lookout, sited about 150m to the W. Within the structure of the wall itself, Baring Gould reckons that there were a number of sentry boxes. These could not be located with any certainty. Dimensions - Overall length of wall including outcrop; ca 450m., NE section; ca 120m., SW section; ca 250m. 81638.1 Large Enclosure Immediately S of the central outcrop is a large enclosure with the appearance of a sheepfold built into a niche of the crag. Semicircular in plan ca 15m x 6.5m, with a possible entrance at the W. The walls are built of piled stones now ca 0.5m and ca 1m wide. Baring Gould states that the site was: ..... carefully explored and afforded ample signs of having been used as a dwelling or shelter for human beings (Baring Gould, 127). A blue glass bead of similar type to those found within the hut group (81631), and a perforated whetstone were found near the entrance. There were also signs of a fireplace. 81638.2 Hut Circle Adjacent to and abutting the NW side of the wall, ca 40m SW of the modern gap, is a distinct hut circle, approximately oval in plan, ca 4.5m x 7m, with walls ca 1.10m wide. There is no obvious entrance. The interior was searched by the Rev Baring Gould in 1898, but only three beach pebbles were found (Baring Gould, 126). The interior still shows signs of the L shaped trench made at the time.