Oweynagat (‘Cave of the Cats’), Co. Roscommon.

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The entrance to the ‘Underworld’
Re-purposed Ogham stone, part of which reads Fraech son of Mebd.

While not of great speleological significance, Oweynagat (‘Cave of the Cats’) I would argue, is one of the most intriguing archaeological monuments in Ireland. Today it feels hidden away and out of sight located, as it is, essentially in the ditch of a modern field boundary. However, as a cave feature it is situated in one the most karstic regions of Ireland (that is, in County Roscommon). As an archaeological monument it forms part of a complex of 50 archaeological monuments that make up the ancient pre-Christian Connaught royal site of Cruachán. It is therefore of special importance as a cultural adaptation of a natural geological feature.

The second Ogham lintel in the souterrain

As it stands today, the above-ground monument of Oweynagat is in poor condition. Originally, an earthen mound surrounded the entrance but this was almost entirely removed in the 20th C. construction of the access laneway (Waddell, 1983). Thankfully, however, what is below ground is preserved in excellent condition. This consists of a double souterrain (which is closed-in on one side) leading, after 3m, to a natural cave. In the building of the souterrain, re-purposing of other archaeological monuments occurred, in which two ogham stones were incorporated as lintel stones in the roof.

Inside the souterrain

One, at the entrance reads Fraech son of Medb. Mebd likely refers to the Queen of Connaught, Maeve, whose bickering pillow-talk with King Ailill over cattle ownership lead to the attempted stealing of the Cow Of Cooley and the rise to prominence of the fearsome and brutal Cú Chulainn. In recent memory, the cave was known as the entrance to the underworld where, at Hallowe’en each year, it served as a portal to and from hell.

From the front of the frame the walls are dry-stone and roof lintels can be clearly seen. At the second light source, about 2m further in, can be seen the beginning of the natural cave

The dry stone walls of the souterrain soon give way to very fine solid limestone walls which open into a long rift chamber. The rift passage form seems to be quite common in this area of Roscommon and there are a number of open similar passages recorded in the surrounding fields (Fenwick and Parkes, 1997) . These, however, are roofless and Oweyngat is by far the most impressive. While only 30m long, the rift is quite impressive and the walls preserve a good degree of moonmilk calcite. For an easy to access spot, it is also relatively clean and undamaged.

The largest section of the natural cave, showing the author and photographer.

NOTE: While this cave is very accessible and well worth a visit, please note that it is protected as a National (Archaeological) Monument as well as a protected habitat under Annex I of the Habitats Directive. It is of great merit that such a monument is open to the public so please ensure that your actions here won’t lead to its damage and the inevitable gating of the entrance!


Fenwick, J., and Parkes, M., 1997. ‘Oweynagat’, Rathcroghan, Co, Roscommon and associated karst features. Irish Speleology 16, 11-14.

Waddell, J., 1983. Rathcroghan – a royal site in Connaught. Journal of Irish Archaeology 1, 21-46.

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