Geophysical survey at Castell Nadolig in 2019 and 2021 by SUMO Ltd for the Royal Commission revealed a possible barrow mound built into the annexe of the hillfort alongside the main gate (although it may be a mounded gateway terminal) as well as several confirmed ring ditches or plough-levelled burial mounds outside the fort to the east. These unusual discoveries increase the likelihood that part of Castell Nadolig’s role involved funerary ceremonies.

The barrows and ring ditches comprise the following:

Newly recognised archaeology: the internal round barrow pair (SN 2986 5041)

Two circular responses (Fradgley 2021: nos. 4 and 5; barrows A & B, Figure 2) within the main hillfort enclosure provide good evidence of a pair of Early Bronze Age ring-ditches or plough-levelled barrows. While the geophysical report suggests ‘It is possible these are indicative of domestic structures’ (Fradgley 2021, 4), the more complete south-eastern circular signature (A) measures 20m x 17m and is far too large for a roofed structure. The recently (2019 & 2021) excavated Dinas Dinlle roundhouse in northwest Wales, one of the largest roundhouses in the region, is 12-13m diameter whereas roundhouse gullies excavated at the nearby Ffynnonwen defended enclosure (discussed above) measured 10.4m and 8.1m diameter (see above; Murphy and Mytum 2011, 280). The partial ring ditch B, measuring 19m diameter, is slightly less clear. Therefore we have good evidence for the existence of two large round barrows on the summit of the hill, which were later enclosed within the innermost ring of Castell Nadolig’s ramparts. In the context of the original objectives of the geophysical survey, these barrows, or potential unenclosed Iron Age graves within or close to them, must be likely candidates for the original findspot of the bronze spoons which were said to have been discovered in the ‘praetorium’ or innermost enclosure of the fort (Barnwell 1862).

Newly recognised archaeology: The annexe barrow (SN 2996 5038)

The eastern, crescent-shaped annexe is clearly visible, and contains what may be a possible barrow at its southern extent near to the main south-east gate, incorporated within later defences. A surface earthwork mound here, thought to be a bastion mound or rampart associated with the gateway, could now be interpreted as a possible standing barrow (Fradgley 2021:  no. 10; barrow C) measuring 18m diameter. The annexe also has a small number of heightened magnetic responses within it, some of which could potentially be unenclosed graves or pits of the type encountered during excavations at Plas Gogerddan, Aberystwyth (Murphy 1992).

Newly recognised archaeology: The external eastern barrow cemetery including a quare barrow (SN 300 504)

In addition to the main structural details of the hillfort, a group of ring-ditches or plough-levelled barrows have been identified to the east of the hillfort. These burial monuments represent a significant addition to the archaeology of the site.

A group of five ring ditches lies between 30-50m east of the outer rampart of the annexe and comprises a circular ring ditch (Fradgley 2021:  11a, barrow E) with an external diameter of 16.8m and a strongly-marked rectangular anomaly (Fradgley 2021:  11c, barrow D) measuring 7m x 9m within a 15m diameter circular area of heightened anomalies. These larger ring ditches are cut by the modern field boundary, but the southern one retains a low barrow earthwork of some 0.2m height suggesting they all once stood as burial mounds.

West of this pair, three smaller ring ditches (barrows F, G & H), each c. 9m diameter, lie in a line with two displaying potential internal burial pits (Fradgley 2021: 11b). The Pembrokeshire Iron Age chariot burial, excavated in 2018, was contained within a penannular ring ditch [1017] with an internal diameter of 10m (K. Murphy pers. comm. 2023), suggesting a likely Iron Age date for these three smaller ring ditches. That said, four ring ditches dating from the Early Iron Age through to the Late Iron Age excavated at Love Lodge Farm, Llandeilo, on the Tywi Valley in 2014 had external diameters ranging between 14m – 15m externally (Hourihan et al. 2015, 36-42).

Some 60m north-west of this barrow group lies a well marked square barrow (Fradgley 2021; barrow I) measuring 6.7m across with a central grave, apparently aligned north-south. This compares well with the largest rectangular early medieval grave excavated at Plas Gogerddan to the north (Structure 373; Murphy 1992, 17-19), which comprised a rectangular foundation trench 5.5m x 3.8m externally. A rectangular conjoined structure between the ring ditches and the hillfort, structure 12, is difficult to classify but may be related to the burial structures.

Extract from Driver 2024.

References:

Barnwell, E. L. 1862. Bronze articles supposed to be spoons. Archaeologia Cambrensis Vol. VIII Third Series, 208-219. https://journals.library.wales/view/2919943/2995579/33#?xywh=-2371%2C-3%2C6921%2C3522

Driver, T. 2024. Castell Nadolig hillfort and the Penbryn Spoons: A new investigation. Archaeologia Cambrensis.

Fradgley, R. 2021. Geophysical Survey Report: Castell Nadolig, Penbryn, Ceredigion. Survey Report 00508, April 2021. SUMO Geophysics Ltd, Upton upon Severn.

Hourihan, S., Long, S. and Simpson, H. 2015. Archaeological Report for Ysgol Bro Dinefwr, Love Lodge Farm, Ffairfach, Carmarthenshire. Volume 1. Unpublished report for Carmarthenshire County Council. AB Heritage Limited and Rubicon Heritage Services Limited.

Murphy, K. 1992. Plas Gogerddan, Dyfed: A Multi-Period Burial and Ritual Site. Archaeological Journal 149, 1-38.

Murphy, K and Mytum, H. 2011. Iron Age Enclosed Settlements in West Wales. Proceedings of the Prehistoric Society Vol. 78, 263-313.