This narrow pathway, stretching 32 metres across the lake, consists of carefully placed stones and boulders that barely break the water’s surface. At just 0.6 to 1 metre wide and rising only 20 to 40 centimetres above the waterline, it’s a subtle yet significant archaeological feature that speaks to the ingenuity of Ireland’s early inhabitants.

The causeway’s rough construction suggests it was built for practical rather than ceremonial purposes, likely serving as the primary access route to the crannog when water levels permitted. Towards its eastern, landward end, the builders incorporated a large natural boulder into the structure, demonstrating their pragmatic approach to construction and their ability to work with the landscape rather than against it. Crannogs, artificial island dwellings built in lakes, were common in Ireland from the Bronze Age through to the medieval period, serving as defensive homesteads for local families or communities.

This particular causeway was brought to the attention of the National Monuments Service by archaeologist Michael Gibbons and documented by Jane O’Shaughnessy in February 2022. Its survival offers a tangible link to the people who once called this crannog home, traversing the narrow stone path daily as they moved between their island refuge and the mainland, carrying supplies, livestock, or trade goods across the waters of Maghery Lough.