Fionnabar's Castle on the summit of Knockma, a large mound of quarried limestone, is probably a neolithic cairn that has been remodelled to look like an Iron age hillfort.
Knockma is a little known site west of Tuam and east of Headford in County Galway. Knockma is the largest of a small series of limestone hills running east - west, each of which was once capped with a neolithic cairn. Several are now gone - destroyed by 'progress', but a large monument remains on the east side of the summit of Knockma. This is called Ceasair's Cairn, and is associated with Ceasair, said to be the first women to set foot in Ireland. She is also credited with being a granddaughter of Noah, and introducing sheep to Ireland; Ceasair is said to be interred within the great unopened cairn which bears her name. It is also said to be another resting place of Queen Maeve, the legendary queen of Connaught, though Maeve's Grave on Knocknarea in County Sligo has a much stronger claim to be her final resting place.
Nearby is another monument called Fionnabar's Castle, a seeming cashel which is said to be another cairn which was re-modelled by a local landlord. This is said to be the home of Fionnabar, the King of the Fairies of Connaught.
Sir William Wilde, father of Oscar describes Knockma thus:
"Cnoc Meadha, or Knockma, the great hill, so conspicuous in the landscape, is about five miles to the west of Tuam, in the barony of Clare and county of Galway; its northern slope is occupied by the woods and cultivated grounds of Castlehacket; and on its summit stands the great carn within which tradition and ancient history say Ceasair, one of the earliest colonists of Ireland, was interred.Tradition, as well as popular superstition, has thrown over it the investiture of fairy legend beyond all other places in the country; for here Finnveara, the Oberon of Irish sylvan mythology, holds his court.
"From this point may be obtained one of the grandest panoramic views in Ireland - the great plain stretching beneath and round Cnoc Rua; the beautiful abbey of Cnoc Muaidhe; the towers of Athenry, the Ford of the King; Tuaim of St. Iarlaith; the Round Tower of Cill Beanáin; the ruined keeps of the De Burgos; the ships riding in the Bay of Galway; the Slievebloom and Clare mountains; the blue island-studded waters of Loch Coirib; and, in the far western background, the Conamara Alps, with their clear-cut edges, and their sides momentarily varying in tints from the marvellous atmospheric effects of that region stretching round by the Partraí range to the lofty peak of Cruach Pádraic; and in the extreme north-western distance the bulky form of Néifin, and even some of the Achaill mountains skirting Clew Bay."
Knockma is about 8 km west of Tuam, just past the village of Belclare. Above is the ruined tower house called Castlehacket. There is now a public nature trail up the hill, with paths. A cottage, recently renovated, at the foot of the hill, is the birth place of traditional musicians Delores and Sean Keane. Parking at the cottage, it is a good 30 minute climb to the top of the hill.
The first Irish Rainbow Gathering was held in the field by the castle at Samhain 1992 (this was aside from the large international gathering held in the Sliabh Bloom Mountains that summer). The festival was great craic, much boosted by the abundance of magic mushrooms growing in the area.
Ceasair's Cairn is located on the highest point of the hill, and commands sweeping views across Galway and Lough Corrib. I would guess that the cairn is about 35 meters in diameter, a similar size to Listoghil in County Sligo, and Cairns T and L at Loughcrew. It appears to be undisturbed and unopened. It is made of quarried limestone much the same as the cairns in the Burren and in County Sligo.
The fairys certainly still own Knockma. This is one of the more wild and untouched hills around the west of Ireland which probably gives a good idea of what neolithic scrubland looked like. Because so much grows around the cairn - the line of trees extends right to its southern side - it is hard to make out how large it is. The surface of the hill is cracked limestone pavement much the same as the Burren, which is quite visible about 50 km to the south.
In the 1950's a local man, who considered himself to be a good friend of the King of the Fairies, had himself buried on the top of the hill. This cross which marks his grave stands by Fionnabar's Castle, about 80 meters west of Ceasair's Cairn. There is a fine view from here, looking south to the Burren.
Fionnabar's Castle is a large stone structure, the exact nature of which is unclear. A seeming cashel, it is probably another large cairn, the stones of which were re-modelled by one of the local landlords. This site is said to be the home of Fionnabar, the King of the Fairies of Connaught. Fionnabar's Castle is a circular monument with two sets of ramparts, much destroyed on the south side. There is a platform top and some steps on the north side. What appears to be two fire pits are placed at the centre of the top. Though there are several forts near the large cairns in the Burren, this monument feels like it was re-modelled in the past, in much the same way the butresses were added to Dun Aengus on Inish Mor.
Looking east from the top of Fionnabar's Castle. Ceasair's Cairn lies in the foreground. Looking in this direction, the Hill of Uisneach, though out of sight, is about 90 km away. The top of this hill is covered with hazel, rowan, briar and heather, quite similar to the scrub found on the Burren karst landscape.
The large cairn, known as Cairn Cesair on Knockma. This mound of quarried limestone is unopened. The cairn is about 35 meters in diameter, and surely contains a large passage and chamber.