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Depressions on a Royal Landscape – The Pitfields of Rathcroghan, Co. Roscommon

The average visitor to the Rathcroghan Complex may come to experience an ancient royal

site of Ireland but leave with a deeper understanding of the interwoven physical and mythical

landscape which spans from the Bronze Age to the Post-Medieval period. Like many Royal

sites one can trace significant periods of domestic and social activity through the unique

archaeological landscape. Rathcroghan offers the opportunity to engage not only with the

physical past of ancient Royal Ireland but also the mythical past. Cruachan is one of

Ireland’s ancient cemeteries, the starting point for An Táin Bó Cuailnge (Ireland’s Iliad) and

home to The Morrigan, a triple goddess of battle, strife and fertility, who resides in

Oweynagat, which is where an enticing ogham inscription referencing two mythical names

from the Ulster Cycle, Freach and Medb, can also be found.

As I child I visited my grandparents, who lived beside Oweynagat, and ever since the sense

of place has stuck with me. After a decade living in Galway city I returned to Rathcroghan as

the Education Development Officer for Curachan Aí Heritage Centre, Tulsk. Since my return

there is one question I have been recurringly asked at the end of a tour of the exhibition

rooms:

“What are those rectangular depressions in the aerial photos of Rathcroghan?”

Description of Features

Dotted across the greater Rathcroghan area, and beyond, are several series of aligned pits.

The extents of these pits are best seen from the air. As a general rule they are orientated

N/NW, but also run N/NE, sometimes in the same group (fig. 1). These features have been

classified by Michael Moore of the National Monuments Service (NMS) as Pitfields, and

defined as “shallow oblong pits c.10m x c. 2-3m, with a depth of c. 0.5m, arranged in parallel

rows placed c. 20-40m apart.” A few of these pits sometimes retain water, which may

suggest a poorly drained area or an area where the water table intersects with the land

surface; however, not all pits in a single group retain water (fig. 2).

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Fig. 1 - Aerial View South of Rathcroghan Mound - Gerry Bracken

Fig. 2 - View of Mucklaghs in winter, showing some water filled pits. - Gerry Bracken

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According to the constantly updated archaeology.ie website ‘pitfields’ only appear in Co.

Roscommon and the majority occur within the wider Rathcroghan area. Moore suggested

that pitfields do not occur outside an area bounded by Castlerea, Bellanagare, Tulsk and

Roscommon town. Martin A. Timoney (2009) has also noted sites outside of this boundary,

expanding the area to isolated locations at Derrynaskea, Co. Longford, and Garranlahan in

Co. Roscommon, and those noted by Tom Condit at Lisserdrea just southwest of Boyle, Co.

Roscommon. The clafficfaction of ‘pitfield’ requires a series of pits, usually a minimum of

three. Timoney’s sites in Derrynaskea and Garranlahan are excluded on these grounds as

there are only two pits visible. It is highly possible however, that other pits in these areas do

not appear on the available aerial photographs. There are twenty-six sites classed as Pitfield

by the NMS which are all located within Roscommon. When one examines SMR sites

designated ‘redundant’ by the NMS there are a further 12 possible sites in the Roscommon

Area, some of which have been identified as swallow holes, while others are noted as not

visible at ground level.

By associating these sites with Rathcroghan one may be tempted to assume that they have an

Iron Age date. This article does not make such claims, and evidence is provided to highlight

otherwise. This said there is no denying that these features appear to centre upon the wider

Rathcroghan complex, as the majority of pitfields occur in townlands associated with this

enigmatic landscape.

Suggestions for Origins of Features

Natural Features

In 1997 Joe Fenwick (Department of Archaeology, NUI Galway) and Mathew Parkes

(Natural History Division, NMI) published an article on Oweynagat Cave in

Glenballythomas, Co. Roscommon, which highlighted the karst features of the region. They

noted a number of ‘curious features in the Rathcroghan area which may reflect the structure

and nature of the underlying geology (Fenwick and Parkes, 1997).

Despite an apparent regular alignment pattern and a suggestion that these depressions are in

some way connected with the unique cultural landscape, an explanation more plausible for

the features as ‘a reflection [of] the underlying karstic landscape of linier rifts’ was proposed

(Fenwick & Parkes, 1997). It was noted that the features ‘display a mutually consistent

orientation and in some instances occur roughly at right angles to each other.’ From this

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observation the writers suggested a relationship to joints in the limestone as the most likely

explanation. Fenwick and Parkes noted further fieldwork is needed to support this theory as

there is insufficient exposed sections of limestone to confirm or deny the theory. Work

carried by Kevin Cormican during the ArchaeoGeophysical Imaging Project (N.U.I. Galway

1995) on a sample of ten pits and a number of exposed geological joints in the area showed

that there are two broad trends for the orientation of the pits at varying degrees of N/NW

(60%) and N/NE (40%). Cormican’s survey reveals a similar percentage for the natural

joints in the region (fig. 3). The limited sample survey showed that there is a possible

correlation between pits and the underlying geology. As this survey was limited to a small

geographical area, and the opportunity to record the underlying karst landscape was limited to

exposed sites. Kevin Cormican examined aerial photos of the region showing possible

glacial features (fig. 4). His analysis of these images identified the ridges as natural glacial

eskers. These features as well as other glacial features have been mapped by Catherine

Delaney of Manchester Metropolitan University. Delaney records the pitfields as

‘rectangular, steep-sided bedrock depressions’ which are present on the surface of the

streamlined hills in the region. She suggests that the likeliest explanation is that the

depressions were created by the ‘plucking of bedrock by overriding ice’ (Delaney, 2009) and

dates them to ice age. Delaney’s report states that initial work was undertaken using aerial

photos taken for the Ordnance Survey in 1973 followed by two days of field-mapping. It is

unclear which pitfields were visited and what other aerial photographic material was at her

disposal. Subsequent work to the OS aerial photos, which would have been available, has

reviled a number of pits on or linear to field boundaries and roads which post-date the Iron

Age activity of Rathcrogahn. The discovery of pits within this context defuses any

suggestion of glacial formations.

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Fig. 3 - Directional trend of Pits (a) and natural Joints (b) in Rathcrogahn Area, Image by Kevin

Cormican.

Fig. 4 - Aerial photo showing eskers to the s/E of Rathcroghan Mound. Photos Gerry Bracken, repoduced

from Cruachan Aí exhibition

Man Made Features

Michael Moore has suggested that these features are man-made and not natural features

proposing a possible ‘post-medieval date, from the 17th

century AD onwards. Moore notes

that “in the same area they will often run in two different directions” (Moore, pers. comm.).

When questioned on a possible origin of these features he made the suggestion that these pits

may represent

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an attempt to mix subsoil with the topsoil. If you think about it, this answers a lot of the

difficulties they present. Whatever came out of them was taken away or spread as there

is never a spoil mound at them. The pits are of a fairly uniform size and shape and set

equally distant apart. This would result if people were spreading the contents over the

ground by shovel.

This suggestion was offered with the caveat that it is not known if this is a regular

agricultural practice and that it may have occurred on a single landlord’s property. The

subsoil is mineral rich and may become beneficial to the fertility when mixed with topsoil

from time to time.

Martin A. Timoney published an interesting article on these features in the Co. Roscommon

Historical and Archaeological Society Journal, Vol. 11, in 2009. His first introduction, like

that of many others, to the features, was in 1972 through photographs taken by Gerry

Bracken, a respected amateur archaeologist / pilot with an interest in aerial photography. It

would seem that until Bracken has photographed the area there was little archaeological

awareness of these sites. The features can be hard to see as their visibility depends on light

direction and grass growth.

Timoney (2009) estimated the count to be 1,500 to 2,000 pits from field walking and aerial

photography available. This figure is a refinement of the 2,500 he suggested in 1990. While

there are many pits visible from aerial photography, there is evidence that many more may

have been filled in over the years. During extensive work by John Waddell, Joe Fenwick and

Kevin Barton in the Rathcroghan area it was reported via a local landowner that ‘some field

banks were levelled and that a number of hollows or pits were filled’ between the 1980s and

1990s (Waddell, Fenwick & Barton, 2009).

Timoney includes pits recorded by the Sites and Monuments Record Team in the late 1990s.

Tom Condit discovered some pits to the south-west of Boyle at this time, which has been

retraced to Lisserdrea townland. Timoney suggested that the twenty or so features are

‘somewhat different in that they are arranged in ‘angled pairs’ rather than straight lines’

(Timoney, 2009, p. 139.). He also includes a pits listed in The Recorded Monuments and

Places manual at Barrinagh to the south of Garranlahan which do not now appear on the

updated archaeology.ie. Upon inspection of this website, this feature has been classified as

redundant noting ‘on an undulating landscape. Said to have been covered in pits with no

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upcast by an informant, but the location was not certain’. The notes in the file for SMR,

RO032-010 state there is no evidence of pits at this location. While visiting the area recently

I saw two such pits at the suggested location. Timoney also includes, ‘hesitantly’ as he has

not seen them on the ground, two pits on a bog island in Derrynaskea, Co. Longford, which

he saw from the air while returning to Abbeyshrule (fig. 5).

Fig. 5 - possible pits on bog island in Derrynaskea, N. of Corlea, Co. Longford. Photos Martin A, Timoney

Possible Dating

The initial suggestion that these sites may be natural is countered by evidence drawing from

context of surrounding monuments and features. Moore has already proposed a post-

medieval date for the features while Timoney (2009) is more careful in his dating. In his

research Timoney (2009) highlights the context in which some of the pits are to be found.

There are a number of instance where the depressions cross archaeological monument and as

such post-date those sites (fig. 6). There are also instances where fieldbanks cross the

features and so the pits pre-date these. Herity (1984) has stated that these banks may be as

early as the 12th

or 16th

centuries but Timoney (2009) dates some to 18th

or 19th

century land

enclosures. While it may not be possible to date the features exactly there is evidence in

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Timoney’s aerial photos to suggest that sites are on man-made and natural features; this rules

out any theory of natural origins.

Fig. 6 - Pitfields N. of N5 at Toberrory T.L N/E of Rathcroghan. Pits shown on glacial ridge top centre

and with field bounday centre. Photos Martin A. Timoney

Possible Purpose

As with the dating of these sites, it may never be possible to uncover the purpose for, or

method, which they were created. There are many local suggestions such as a source for clay

or rocks, the collection of water, storing potatoes, drainage, flax pits, damaging fields owned

by a landlord, military activities and producing lime (Timoney, 1990). Another suggestion

passed on by Timoney from Leo Leydon, a Sligo fieldwalker who had a close association

with Rathcroghan some years ago, is that soil was removed and offered in a ritual manner as

material for the construction of some of the major archaeological monuments.

Suggestions from visitors to Cruachan Aí range from the practical to the bizarre. It has been

suggested that these pits may be the archaeological remains of temporary camps or huts,

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created by the removal of soil and placing of a wooden or shrub mats to create a floor to

prevent dampness. A suggestion was also made that these sites may have been traps, and a

means of defence. While the musing of possible uses for these pits always provides for an

interesting conversation with visitors to the centre their suggestions are made without

context.

Fig. 7 - Pitfields N. towards Rathcroghan from Glenballythomas T.L. Photos Martin A, Timoney

Possible Future Work

The significance of these enigmatic pits may never be fully understood without detailed

mapping, geophysics, excavation and soil testing and while there is merit in studying the

geological landscape, it should also be remembered that Rathcroghan is a spiritual landscape

with many archaeological features covering a substantial time period from the Neolithic to

Medieval. Timoney (2009) notes the ideology of Prof. Peter Woodman; ‘that we do not

know everything, or even near it, and we should keep the material that we do not understand,

perhaps even more so than we can understand’. While there has been intermittent interest in

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these sites over the years, they have not been extensively studied within the Rathcroghan

area.

In order to gain a greater understanding of these sites an archaeological mapping of all known

and suspected pitfields with a follow-up detailed investigation of a number of pitfields should

be conducted. The area north and south of Rathcroghan provides ample opportunity to

examine these features both via non-invasive and excavation methods

While writing this article I tried in vain to find detailed aerial photography online, which

showed these pits clearly until on afternoon I was checking my location using my mobile

phone. Google Earth has a detailed aerial plan for the Rathcroghan area, which highlights

many of the Pitfields clearly, so that they can be mapped and checked at ground level. Using

a program called GPS Essentials designed for the Android phone I mapped a series of

waypoints highlighting areas of definite and possible sites which can be mapped in detail at a

later date using more precise GPS equipment. A prime example of a pitfield can be located

on Google Earth in the townland of Glenballythomas N53 47.403, W008 18.311.

An opportunity to discuss these sites and the wider Rathcroghan archaeological landscape

will be provided at the Rathcroghan Conference April 13th

- 15th 2012 at Cruachan Aí

Heritage Centre, Tulsk, Co. Roscommon. These unique rectangular features will be

discussed, among other things, during this conference with the intention of unravelling the

enigmatic nature of the local archaeology by viewing advances in technologies and various

interpretations of the landscape.

Acknowledgements

I wish to thank Martin A. Timoney for permission to reproduce some of his aerial photos and

for commenting on several versions of this article, Joe Fenwick, John Waddell and Kevin

Barton for their support and work for the Cruachan Aí Centre and Michael Moore of the

National Monument Service and Kevin Cormican who provided data for this article.

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Blurb: Gary Dempsey is the Education Development Officer at Cruachan Aí Heritage Centre

Tulsk, Co. Roscommon, and organiser and contact for the Rathcroghan Conference 2012. He

is a graduate of M.A Irish Studies at NUI Galway and B.A Heritage Studies G.M.I.T Galway.

Details of conference http://www.rathcroghan.ie/festivals-and-conferences-in-roscommon/

Bibliography

Timoney, Martin, “Sub-Rectangualr Pits and Pitfields in Central North Roscommon” in Co.

Roscommon Historical and Archaeological Society Journal, Vol. 11, 2009, pp. 139-143.

Fenwick, Joe, and Parkes, Mathew, “Oweynagat, Rathcroghan, Co. Roscommon and

associated karst features” in Irish Speleology The Journal of Irish Caving, Journal of the

Speleological Union of Ireland, No. 16, 1997, pp. 11-16.

Waddell, John, Fenwick, Joe, and Barton, Kevin, Rathcroghan Archaeological and

Geophysical Survey in a Ritual Landscape, (Wordwell, 2009).