Staigue Fort is probably the finest example of a stone fort in Ireland and is about 2500 years old. It is built of stone common to this district and is almost circular, 27 metres in diameter. The wall almost 4 metres (13ft) thick at the base and 2 metres (7ft) thick at the top. The north side is still perfect with some of the old coping stones, 90cm (3ft) long, still in position. The wall is 5.5 metres (18ft) high on the north and west sides. It has a square-headed doorway and inside are two small chambers. One on the west side and another on the north. The stairways, which are probably the most interesting feature of the fort, run inside the wall almost to the full height of the wall, and these stairs lead to narrow platforms on which the fort's defenders stood. The fort holds a dominant place in the folk culture of the Iveragh Peninsula.
It is situated three miles from Sneem and it stands on a low hill in an amphiteatre of rugged hills open to the sea on the south. The interior of the fort is reached through a 1.8m (6ft) high passage roofed with enormous double lintels. Access to the ramparts is gained by a series of steps in the shape of the letter X. The fort is surrounded by a large bank and ditch, still very obvious on the north side. Staigue Fort shows great skill in building. No mortar was used, the stones were not dressed and it is similar in style to the Grianan of Aileach in Co. Donegal. The dating of this site is difficult but it may have been built in the centuries preceding St Patrick, during the Celtic period. Dr Peter Harbison, however, suggests that the earliest possible date for construction is probably around the first century BC.
During the 19th century its construction was in turn assigned to such unlikely groups as Phoenicians, Cyclopeans, Danes, and Arch-Druids, while equally implausible theories were put forward concerning its purpose. Local lore has it that the inhabitants were small in stature and they came here in search of ore. There is evidence that copper was excavated in the surrounding countryside.