A crannog is an artificial or partially artificial island, typically built from layers of timber, peat, brushwood, and stone, and used as a dwelling place. They were constructed across Ireland and Scotland from the Bronze Age onwards, with many remaining in use well into the medieval period, sometimes as late as the seventeenth century. The fact that one occupies this particular stretch of Mayo water is, in itself, a small reminder of how densely this island was once settled in ways that left almost no trace above ground.

Crannogs were chosen for their defensive advantages. A family or small community living on an island, even a man-made one only a short distance from the shore, had a meaningful buffer against raiders and rival clans. Access was typically controlled by a single causeway or a dugout canoe, making an uninvited approach difficult. Many crannogs were occupied across several centuries and by successive generations, accumulating deep organic deposits that preserve organic materials, such as wooden tools, leather, and food remains, far better than dry land sites tend to do. The Drumady example is recorded as a monument, which places it within a recognised class of protected archaeological site, but detailed information about its date, construction, or excavation history remains sparse in what is publicly available.