³ James O’Driscoll (2019) "Picture Perfect: Using Drone Technology and Photogrammetry Techniques to Map the Western Stone Forts of Ireland," Journal of Field Archaeology, 44:2, 133.
According to the author, "The inland promontory fort of Knockdhu is the only example that has been excavated (Macdonald 2008; 2012). This revealed the fort was initialy constructed around the end of the Middle Bronze Age, c 1400 BC."