A circular stone tower stands on the highest point, 32m above OD, towards the western end of the headland of Trwyn Castell (NPRN 801137), at Abereiddy/Abereiddy. The date of construction of the tower is unclear. It is annotated as a 'summerhouse' on an historic Admiralty chart published in 1842, but is considered to be of 18th century construction in its HER entry (PRN 58661), and to be c.1800 in its listed building entry (12408). Its function is variously described as a lookout tower, or as a navigation marker for coastal shipping. Both are plausible.
The tower is neatly built of roughly coursed stone, mortared together. One storey high with apparently the remains of a gently slopping single-pitched roof of slate slabs supported on timber beams, of which only one survives. There are three equally spaced windows each much the same size, with evidence for frames surviving in the plaster. Between these window spaces are, at the NE, a doorway, at the S a fireplace with square chimney within the wallspace and at the NW a shallow alcove with wooden lintel. The name H+M GILLESPIE has been carved into the stone above the fireplace. The window spaces and the door space are topped with slate lintels. The tower has an external diameter of 4.8m, internal diameter of 3.4m, and maximum height of about 3.5m.
The tower was visited by the RCAHMW on the 30/10/2024 and recorded with a photogrammetry survey (links below).
Sources include:
Cadw Listed Building 12408: https://cadwpublic-api.azurewebsites.net/reports/listedbuilding/FullReport?lang=&id=12408
Dyfed Archaeological Trust HER PRN 2732: https://archwilio.org.uk/her/chi3/report/page.php?watprn=DAT2732
Dyfed Archaeological Trust HER PRN 58661: https://archwilio.org.uk/her/chi3/report/page.php?watprn=DAT58661
Historic Admiralty Chart 1410_A1, RCAHMW digital collections sourced from the UK Hydrographic Office and published in 1842 .
Latham, J. Report for the National Trust: "Ynys Barri", 1989.
RCAHMW Photogrammetry Survey, PGS2024_026: https://skfb.ly/p8uAn
J. Whitewright, RCAHMW, November 2024.