In Retrospect: A centennial look at Thomas J. Westropp's field records of the promontory forts of north County Mayo

In August 1910 Thomas J. Westropp visited a number of promontory forts in north-west County Mayo, including two very impressive examples: Doonamo on the Mullet Peninsula and a fort he called 'Dun Kilmore' on the island of Achillbeg. With customary diligence he described and commented on his findings in a paper published in the Proceedings of the Royal Irish Academy. The paper, Notes on the larger cliff forts of the west coast of County Mayo (Westropp 1911, 11-133) is the subject of this retrospective. These particular forts were visited to provide context for the multi-disciplinary Clare Island Survey of 1909-11, to which Westropp contributed the archaeological and historical section (Westropp 1911, section 1, Part 2, 1-2.78). The 'cliff forts' paper also formed part of a long series of articles by Westropp on Irish promontory forts, published in the journals of the Royal Irish Academy and the Royal Society of Antiquaries of Ireland between 1906 and 1922. 1 The protracted fieldwork involved the greater part of it carried out in the years 1906 to 1915 saw Westropp visit most of the (then) known promontory forts along the western and southern coast-line.2 Along the way he discovered or brought to official attention a great number of other unrecorded forts. Subsequent work on the Leinster forts was curtailed by his early death at the