A crannog is an artificial or partially artificial island, typically constructed in a lake or wetland, and used as a dwelling place from the early medieval period onwards, sometimes as late as the seventeenth century. They were built by driving timber piles into the lakebed and piling up layers of stone, peat, brushwood, and other material, creating a defensible platform that was difficult to approach without a boat. The example at Moanogeenagh has left almost no trace in the accessible record, which is itself a kind of quiet curiosity, a site that is formally recognised as a monument but whose particulars remain, for now, largely out of reach.