Name Grianan of Aileach County Donegal Nearest Town Letterkenny Access Road N13 More Virtual Tours Click for more About The Grianan of Aileach is a group of historic monuments in County Donegal built on the hill of Griann which is 244 metres high.

Most writers have identified the site as being the great royal fort of Aileach.
The main monument is that of an Iron Age stone fortress.

 
It is generally accepted to be the seat of the Kingdom of Aileach although the true capital is now believed to lie further to the east.

The kingdoms of Ulaidh and Kingdom of Oiralla were two subject kingdoms in the North under the general rule of Aileach.

Whatever its true status, the Griann was a historical centre of culture and politics during the rule of early Irish chieftains (circa.
800 -1200 B.C.
).

An Irish creation myth claims that this fortress was built by the great king Daghda of Tuatha de Dannan.

The grave of the king’s son Aeah was in the centre of the fortress, which had been built around it.

Whether such a grave existed is unknown; there are no archaeological remains, although a nearby tumulus could be a grave marker.

By the 12th century, the Kingdom of Aileach had become embattled and lost a fair amount of territory to the invading Normans.

The fortress itself was destroyed by Murtaigh OBrien, King of Munster in 1101.

By around 1177, the Normans controlled large portions of lands once held by AileaLocated just outside at the village of Lisfannan, 27 kilometres east of Letterkenny in County Donegal, this was the site of a sixth century monastic settlement founded by St.
Mura, but nothing remains of that now.

The cross slab is quite large – 1. 6m tall x 1m wide – and has a large Latin cross carved on both sides.

The west face also has two figures with long hair.

Down one edge is one of Ireland’s few Greek inscriptions.