In 2017 Dinas Dinlle became the focus of new archaeological and palynological research and survey work as part of the 2017-2023 EU-funded CHERISH Ireland-Wales project. In August 2019 the Gwynedd Archaeological Trust was funded by CHERISH to run a 3-week evaluation excavation involving local volunteers.

Within the hillfort, during an evaluation excavation targetting anomolies identified in a CHERISH funded Magnetometry Survey (Hopewell, 2018), Trench 2 provided evidence for a small roundhouse (6.4m internal diameter) with internal post holes and a clay floor. This abutted a low revetment wall and metalled floor surface. This roundhouse contained no Roman material, suggesting an Iron Age date, and had been filled with midden material post-abandonment.

On the north side of the roundhouse pits and a shallow ditch were found, sealed by a layer of buried soil which contained a small iron chisel. In the ditch was a small iron hammer head, which may be the first tool of its kind to have been discovered in Wales. Its weight (less than 100g) suggested that it had been used for delicate work. The pits, ditch, and hammer are likely to be contemporary with the occupation of the roundhouse. It appears that after a period of disuse and abandonment, the roundhouse partially collapsed and was sealed by repeated layers of windblown sand, over an extended period of time.

This roundhouse was found 20m south of the larger roundhouse (NPRN 703001), which may represent a later phase of occupation, as it contained both Iron Age and Roman artefacts.

A second season of excavation during August-September 2021 reopened and extended Trench 2. Gwynedd Archaeological Trust undertook the work with funding from Cadw, National Trust, CHERISH and the Welsh Areas of Outstanding National Beauty (AONB) (Sustainable Development Fund).

References: 

• Hopewell, D. 2018. Geophysical Survey at Dinas Dinlle Hillfort, Llandwrog, Gwynedd. GAT Report No. 1434. http://www.walesher1974.org/her/groups/GAT/media/GAT_Reports/GATreport_1434_compressed.pdf

• Hopewell, D. 2021. An interim summary of the results of the excavations at Dinas Dinlle (2019 and 2021). Gwynedd Archaeological Trust. 

• Hopewell, D, and McGuinness N. 2022. Dinas Dinlle: Excavation of an eroding hillfort. Interim report – community excavations 2021. GAT Report No. 1628. http://www.walesher1974.org/her/groups/GAT/media/GAT_Reports/GATReport_1628_compressed.pdf

• Lynes, M.S.; Ferreira, C.; Oattes, A.M.; Jones, B.; Evans, R.; McGuinness, N. and Ryan Young, C. 2021. Dines Dinlle archaeological evaluation excavation: Final Report. Project No. G2608, Report No. 1582. Historic Environment Record Event Primary Reference Number: 4547. http://www.walesher1974.org/her/groups/GAT/media/GAT_Reports/GATreport_1582_compressed.pdf  

H. Genders Boyd, RCAHMW for the CHERISH Project, 2022.