1. A small coastal promontory fort measuring approximately 77m north-south by 30m east-west, attached to the mainland by a narrow neck 17m wide. Across this neck are bivallate promontory defences, comprising an outer short (c.15m) length of bank on the west side with an inner rock-cut ditch, and an inner bank c. 1.5m high, with a rock-cut ditch crossed by an entrance causeway of unexcavated rock. Today the area enclosed is around 0.14 hectares.

In March 2022, the EU-funded CHERISH project (RCAHMW) noted new erosion and collapse on the west-central side of the promontory during coastal monitoring. Collapse of the bank revealed sections of stone walling. Ground and UAV photographs were taken to record this.

2. On 10th December 2024, a new drone photogrammetry survey of the promontory fort was undertaken with the permission of Pembrokeshire Coast National Park Authority. This included topographic survey on the ground of the key structures, revealing good rock-cut faces beneath undergrowth in both the promontory ditches. A Digital Terrain Model from the drone survey shows that the original encircling rampart of the promontory fort survives well on the south (gateway), west and south-east sides, but has likely been totally lost to erosion on the north-east and north sides.

The nature of this enclosing bank around the fort potentially suggests an Early Medieval, rather than Iron Age, date for this main enclosure. In the area are several Early Medieval monuments, including a chapel and cemetery at St Bride’s Haven (NPRN 544132). However, the 2024 drone survey also shows a very low outer promontory earthwork, continuing east on a slightly different alignment to the short outer defensive bank and originally cutting off the wider promontory. This low earthwork may suggest that the current form of the promontory fort is a rebuild of an earlier structure, potentially Iron Age but perhaps even earlier.

The interior and headland remain heavily overgrown with bracken, blackthorn and brambles making access and survey extremely difficult. The December 2024 UAV survey was flown just after Storm Derragh, a major storm with northwesterly winds, which had the effect of flattening the coastal vegetation to a degree providing timely conditions for photogrammetry.

The 2024 Sketchfab model can be seen here: https://skfb.ly/psWSs

2. On the headland adjacent to the promontory fort are a set of denuded First World War practice trenches, largely obscured by bracken (NPRN 421967). These show well in the drone model.

Toby Driver and Louise Barker, CHERISH Project/RCAHMW, 5th May 2023. Updated 19th December 2024

CHERISH PROJECT 2023. Produced with EU funds through the Ireland Wales Co-operation Programme 2014-2020. https://cherishproject.eu/en/

CHERISH (Climate, Heritage and Environments of Reefs, Islands and Headlands) is an EU-funded Wales-Ireland project (2017-2022) led by the Royal Commission on the Ancient and Historical Monuments of Wales, in partnership with the Discovery Programme: Centre for Archaeology and Innovation Ireland, Aberystwyth University: Department of Geography and Earth Sciences and Geological Survey, Ireland.

Site Record

Castle Head coastal promontory fort