Situated 7km west of Derry, Grianian of Aileach perched on the summit of Greenan Mountain.The name Grianian of Aileach Translates to stone palce, temple or fortress of the Sun. Although heavily restored, there are no doubts as to the antiquity of the site as it is one of only five Irish locations marked on Ptolemy of Alexandria’s 2nd century map of the world.
The stone ringfort is thought to have been built in the early years AD and from the 5th to the 12th centuries it was the seat of the northern Ui Neill, the rulers of the Fifth of Ulster.
According to the Irish Annals, Grianan of Aileach was destroyed in 1101 by Murtagh O’Brien, the ruler of the Fifth of Munster, as a reprisal for the Ui Neill’s destruction of his royal seat at Kincora some thirteen years before. The account tells that O’Brien would settle for nothing less than complete destruction of the Ui Neill stronghold and ordered each of his soldiers to carry away a stone from the fort as they departed.
Restoration was carried out between 1874 and 1879 by Dr. Walter Bernard , a Derry antiquarian. .
The Fort is of dry-stone construction and the the outer surface of the 5m high walls has a graceful curved, or battered, form. There are excellent views from the fort across Lough Swilly, Lough Foyle and the Inishowen Penninsular, it is claimed that on a clear day five of the nine counties of Ulster can be seen from this viewpoint.