[1][2] Donaghmore Souterrain is located 3.6 km (2.2 mi) west of Dundalk, near a cluster of houses.

[3][4] Souterrains are cave-like structures built as places of refuge and storage, and in Ireland they date between the 8th and 12th centuries.

[5] The souterrain was discovered in 1960 during the construction of a Louth County Council cottage.

It was excavated by Etienne Rynne who found trenches, a pit, two post-holes, sherds of souterrain ware, a bronze pin, a whetstone and iron slag.

[citation needed] The souterrain at Donaghmore is a complex of tunnels lined with dry stone walls, floors and ceilings, with corbels and lintels.