²³O’Driscoll, James. “Picture Perfect: Using Drone Technology and Photogrammetry Techniques to Map the Western Stone Forts of Ireland."
Journal of Field Archaeology, 44:2, 126-146. p. 135.
The author writes, "Using aspect analysis, we can see that there are subtle and evenly spaced depressions in the northern section of the inner wall. They are approximately 4.6–6.1 m apart, and could represent evidence that the hillfort was constructed by groups or gangs of people, with each gang (or every season) constructing a section of the defenses that would later be joined together."