Dún Eoghanachta, pronounced ‘Onacht’, is a stone fort found in the western head of Inis Mór island. The fort takes its name from the Eoghanacht tribe of Munster who were associated with the island in Medieval times. The exact date of its construction is not known, but it is probably Iron Age.
Almost 90 feet in diameter, the fort consists of a circular single two terraced wall, 16 ft high and over 12 ft thick. The walls have stairs in several places. Most interestingly, within the walls the remains of one of several clochan (beehive huts) can be found.
Excavations in 1995 found deposits that revealed remains of hearths, animal, and shell remains, and some iron objects.