Cuilcagh Mountain monuments

Over a hundred boulder monuments were discovered by Dr Alasdair Kennedy on Cuilcagh Mountain, the most prominent mountain in this part of Ireland. It is amazing to find so many monuments on top of this major mountain which would have been most inhospitable location in those distant times. These discoveries were made between Autumn 2015 and Summer 2016.


Most of the hundred boulders are propped. There is a wide variety of examples with many resembling the several hundred already identified in the wider area. There are also a number of spectacular, unique, examples. Many of the monuments are in prominent positions, some are skylined on the mountain cliff edge, several have stacked props. The discovery of so many monuments on Cuilcagh, although no surprise, is particularly significant given the central role this mountain must have had in this whole region.

A few examples of Cuilcagh monumental boulders:

Cuilcagh Mountain monuments report  by Alasdair Kennedy, BSc, PhD. (Extracts)

This report provides an outline of the archaeological discoveries on the Cuilcagh mountain plateau in counties Fermanagh and Cavan.  Its main focus is on the numerous boulder monuments which have been erected on the plateau in prehistoric times, which were first identified here in October 2015.  Since then a number of field trips have been made to survey the Cuilcagh plateau and document the boulder monuments there.  The study builds on the work of Burns and Nolan (2017) in recording and analysing the boulder monuments of the Burren-Marlbank area. Download full report here –

Kennedy Cuilcagh report 2017 .pdf 1 MB

Cuilcagh mountain dominates the skyline of  the Fermanagh-Cavan border, and from its summit (on a good day!) can be seen a large part of the northern half of Ireland.  It has a distinct profile when viewed from the north, forming with the Marlbank uplands a dramatic backdrop to the Lower Macnean valley. The Cuilcagh plateau extends for 4km north-west from Cuilcagh summit (666m) to Tiltinbane (596m), with an area of approximately 1km² above an altitude of 600m.  A 3km long curved ridge extends south-west from the summit, descending gradually to around 530m before dropping steeply to the Bellavalley Gap. The northern edge of the plateau is fringed by cliffs (fig. 1).

A number of prehistoric archaeological sites are recorded in the Sites and Monuments Records of Northern Ireland and the Republic of Ireland. The most obvious one is the large cairn on the summit of Cuilcagh (FER 258:001/CV006-001), and nearby are several hut sites (CV006-003001, CV006-003002, CV006-003003).  Less obvious is a smaller and more damaged cairn (FER 243:024, Laght a Phelim) on the other end of the plateau, 4km north-west of the Cuilcagh cairn.

The 2015 to 2017 field work on Cuilcagh has revealed other monuments scattered across the plateau, bracketed by the two cairns (fig. 3 – Map). The vast majority of these comprise boulder monuments, single boulders which have been repositioned and modified in a variety of ways.  Boulder monuments are far from obvious anthropogenic constructions, since they are generally comprised of only a few components, unlike megalithic tombs, stone circles, hut sites, etc.  It can be argued that in a post-glacial landscape such arrangements of boulders could arise by chance.  In order to support the extension of prehistoric activity to the whole plateau, primarily through the construction of boulder monuments, it is necessary to find evidence that these particular combinations of stones are of anthropogenic origin

One unique example, CGH35, is an evidence boulder comprising a boulder which has been split into three sections.  Two of these are CGH035a and CGH035b, part of a setting of three boulders (including CGH035c) which has been called the ‘Druid’s Chair’.  CGH035a and CGH035b are two stones split from one boulder.  CGH035a is the ‘Druid’s Chair’ itself, a boulder split in such a way as to form the shape of a seat with a backrest. (Name is based upon its uncanny similarity to the Cavan Burren example, see Rocking Stones page).  In addition it is propped and very finely balanced along one lower edge.  Its partner CGH035b is a triangular prism formed by the splitting of CGH035a.  It was apparently propped, but has at some point been­ tipped over; the ‘shadow’ of the original position of the boulder can be seen when the surface of the bedrock is wet, and a small rock sits on this less-weathered area which is presumed to be the prop (fig. 4).





Geological evidence boulders

There are several boulders on the Cuilcagh plateau whose current position can be shown to be unnatural with regards to the geological events which have shaped the plateau (see CGH050a, CGH076, CGH099a).  Two of these geological evidence boulders are considered in detail, CGH050a and CGH076.  CGH050a (figs 8 & 26) is situated on the north-eastern side of the plateau.  It is a double propped boulder which bridges over a large rift.  The sequence of geological events is shown in figure 9.  It commenced with the deposition of the boulder during the last glaciation.  As the ice retreated from the lower slopes of the mountain the rift developed, with the edge of the plateau moving to the northeast.  Furthermore, the rock on the southwest edge of the rift moved downwards. Therefore, had CGH050a been propped naturally during its deposition from the ice, it is highly unlikely that the props would have remained trapped underneath during the subequent faulting.


Another boulder presenting strong geological evidence is CGH076 (fig. 10), which has an unusually placed micro prop between a vertical face of the boulder and the vertical face of the rift which the boulder bridges across.  The rift has developed along the south-western edge of the plateau.  The geological evidence is interpreted as the deposition of the boulder during glaciation, followed by the opening up of the rift as the ice retreated from the Glangevlin valley.  Consequently it is extremely unlikely that the small rock could have remained or been trapped behind the boulder as the rift opened up.  This boulder in particular may be of interest to geologists, as it shows that the rift it is placed over has not enlarged since the side prop was placed in position.

Two new terminologies have been developed from the Cuilcagh plateau study to describe the repositioning of boulders within the landscape  1] Perched boulders 2] Plinth.

1] Perched boulders are those which are elevated above their surrounding ground level, raised on an outcrop of bedrock, and they may be skylined from certain direction. 

2] Plinth indicates where a surface which extends beyond the boulder to distinguish it from the more common pedestal where the boulder extends beyond it.  Many boulder monuments on the Cuilcagh plateau rest on plinths.  

CGH030 demonstrates well the propping and perching characteristic of Cuilcagh boulder monuments (fig. 12).  It is a large slab of sandstone which has been propped with a single rock, and perched on a flat plinth of sandstone bedrock, which it also overhangs; thus two spaces have been created underneath the boulder.  Other remarkable examples of perched boulders appear skylined along the northeast and southwest edges of the plateau from the lower ground, such as CGH001, precariously propped and perched on the very edge of a cliff (fig. 13).  Within the perched boulder category are some standing stones, prominent unpropped boulders within the blockfield, such as CGH022 (fig. 14).  Another standing stone, CGH038, is surrounded by a kerb (fig. 15).  




Among the propped plateau boulders are four recurring characteristics which require further research.

1] A number of small propped boulders.
2] Propped boulders which have a prop which extends markedly beyond the edge of the boulder it supports.
3] Perched boulder which has been positioned over the rifts that fringe the plateau, which we termed ‘bridging’.
4] An intriguing recurrent geometrical form in which a boulder is propped to create a triangular or pyramidal profile.

1] Small propped boulders are loosely categorised as having a longest dimension of less than 0.5m. Such monuments are fragile, and, assuming that they once proliferated in the valley megalithic communities, have only survived on Cuilcagh by reason of its remoteness. These might represent boulder monuments created by small groups or even individuals. Examples are provided by CGH017 (fig.16) and CGH090 (fig. 17). There are several other examples.



2] A prop which extends markedly beyond the edge of the boulder it supports, for example, CGH071 (fig. 18), cannot have served any special structural function so it is concluded that there was a deliberate choice made to extend the prop for some aesthetic reason. There are several other examples.



3] A type of perched boulder which is ‘bridging’ over a rift. In CGH010 (fig. 19) the prop serves to elevate one end and enhance the point of the boulder. There are several other examples. In CGH010 (fig. 19) the prop serves to elevate one end and enhance the point of the boulder, while in CGH014 the prop raises the bridging boulder to the horizontal position creating a table boulder (fig. 20).


Five of these pyramid propped boulders have been recorded (CGH015, CGH057, CGH069b, CGH96, and CGH102), and one pyramid boulder without an apparent prop (CGH043) (fig. 21).


4] A boulder that is propped to create a triangular or pyramidal profile. Five of these pyramid propped boulders have been recorded, one example is CGH043 (fig. 21). Boulders positioned in such a way have strong directional aspects (azimuth and elevation), besides having a distinctive shape.


Fossil basin

The researchers have identified two features peculiar to the Lackagh sandstone which forms the Cuilcagh plateau, which the constructors of the boulder monuments appear to have intentionally incorporated into their designs.  These are beds of small rounded quartz pebbles, and imprint fossils of extinct plants related to clubmoss and horsetail (lepidodendron and calamitaceae).  Many instances of each have been recorded, and they are revealed both on the boulders and on the plinths.  CGH039 is a good example, a propped boulder sited on a plinth which shows both the quartz pebbles and a fossil imprint basin (fig. 22). The pyramidal propped boulder, CGH015, is also aligned with a fossil imprint basin (fig. 23).  Both the fossil imprint basins and the quartz pebbles must have had ritual significance.  


Also of note among the Cuilcagh plateau monuments are the ice-scoured boulders and sandstone outcrops, worked into fantastical forms during the glaciation. Of particular note are propped boulder CGH065b, which stands upright, with two prominent bosses on top – the similarity of these with breasts has led it to be dubbed ‘Madonna’ (fig. 24). Also of note is propped boulder CGH066, whose fluted form also has a feminine appearance (fig. 25)


The communities of the Burren-Marlbank area are in many ways backdropped by the bulk of Cuilcagh.  Many generations have come and gone here, and all have left their mark on the landscape in some way: from the prehistoric hut sites, relict walls, cairns, megalithic tombs, and boulder monuments scattered across the Burren-Marlbank; to the present-day Marble Arch Caves UNESCO Global Geopark which seeks to recognise the value of this landcape and introduce it to present generations while conserving it for future generations.  What is remarkable is the attraction of the mountain itself: prehistoric monumental alignments in the Burren indicate the Cuilcagh cairn; a modern ‘staircase to heaven’ draws thousands of visitors to the summit!