Rathcroghan: a living and unexplored ceremonial complex

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TULSK, Ireland –  Rathcroghan (Ir. Cruachan Ai), was the ancient capital of Connacht. It may be the oldest and largest unexcavated “royal” site in Europe. Fewer people know about it, than know about Navan Fort (Ir. Emain Macha) or Tara (Ir. Teamhair). Yet, the ancient Irish epic, the “Tain Bó Cúailnge” begins in Cruachan. Queen Medb lived there. Oweynagat (the Cave of the Cats), an entrance to the Irish Otherworld, is located in Rathcroghan. That cave has strong links to the Mórrígan, a complex, major Irish goddess.

Kite aerial photograph of the Multivallate Ringfort at Rathrá, Co Roscommon, Ireland. Photo Credit: West Lothian Archaeological Trust (Jim Knowles, Frank Scott and John Wells, CC BY-SA 4.0]


The ancient people of Connacht would gather at Cruachan in great assemblies. On that site, they would inaugurate kings or chieftains. They would hold major religious festivals, burials, fairs, and games there. The custom of inaugurating rulers at Rathcroghan lasted until 1643. Six years later, Oliver Cromwell invaded Ireland with catastrophic and bloody results. In 1938, Douglas Hyde was inaugurated there as President of Ireland. In 2010, a modern Bealtaine festival took place on the Mound of Rathcroghan.

The Rathcroghan complex contains over 240 known archaeological sites. The earliest site dates to about 3500 B.C.E.  By 800 C.E., people had abandoned Cruachan as a Pagan center. The complex covers roughly 6.5 sq km (about 2.5 sq miles).

The Rathcroghan Visitor Center organizes tours, staffs the museum, and runs the café. The Centre argues that Samhain practices at Rathcroghan evolved into Halloween.

Unlike the ancient Greeks, no Irish Pagan wrote about their myths and rituals. Irish Paganism lost its elite support in the Fifth Century, as Christianity took hold. Medieval Christian scribes wrote about Otherworldly creatures from Ireland’s Pagan past. Some myths and rituals survived as folklore. Over the centuries, that folklore evolved.

The practices of the ancient Irish Pagans occurred in physical structures. Those physical structure left remains in Rathcroghan, Navan Fort, and Tara. From those remains, people today can infer some of their practices.

To learn more about ancient Irish Paganism, people today have to explore archaeology, folklore, and medieval literature. Lora O’Brien used to manage the Rathcroghan Heritage Site and notes that the location was originally called Cruachan Ai, and was changed to Rathcroghan Visitor Centre under O’Brien’s management. O’Brien wrote that the area is a whole complex called Cruachán or Rathcroghan, which surrounds the center. That site has since become the Rathcroghan Visitor Center. Now, O’Brien leads the Irish Pagan School. O’Brien has produced a special series of YouTube videos on the Mórrígan and on Irish Paganism.

Archaeologist John Waddell has published an article, “Rathcroghan – a Royal Site in Connacht.” While somewhat dated, his article discusses the medieval literature and archaeology of the site. Waddell reported that the ancient Irish scribes frequently referred to Rathcroghan. Skeptical of their historical accuracy, he summarized many of those references.

Medieval scribes described Rathcroghan as a place for assembly. In the “Triads of Ireland” (9th Century), three fairs are mentioned: one at Telltown, one at Colman Elo, and one at Croghan. The fair of Telltown (Óenach Tailten) lasted into the 19th century. Waddell quotes another archaeologist, F. J. Byrne. He described these fairs as multi-faceted. They were political assemblies, market-fairs, and “occasions for general jollification.” They involved games and horse-racing. Frequently, these fairs occurred on the site of ancient cemeteries.

Waddell argues that Rathcroghan had religious importance. Medieval scribes referred to it as the burial place of kings. Waddell describes the site as containing four types of monuments: 1) funerary or ceremonial mounds, 2) linear earthworks and ancient trackways, 3) enclosures, and 4) platform earthworks. Most of the monuments are burial mounds. For the sake of brevity, this article will focus on two Oweynagat and Daithi’s Stone.

Oweynagat or the Cave of the Cats

Rathcroghan contained an entrance to the Otherworld, Oweynagat. Unsurprisingly, more folklore has evolved around this entry point than any other structure in Rathcroghan.

Entrance to Oweynagat (the Cave of Cats). The gateway to the Otherworld, the birthplace of Queen Medb, and where the Mórrígan emerges at Samhain to spread winter [Photo Credit: Gillaween, CC BY-SA 4.0]

In their YouTube video, “The Mórrígan’s Cave – Oweynagat, at Rathcroghan/Cruachan, County Roscommon, Ireland,” O’Brien discussed Queen Medb’s descent into the Oweynagat.  She emerged with three giant cats. Medb used these giant cats to test three warriors arguing about who was best. In another story, red birds flew out of the Oweynagat bringing pestilence. In yet another story, pigs emerged from the cave. Everywhere they clawed the ground, the land became barren for seven years. At Samhain, the Ellen Trechen, a three-headed monster came out of the cave.

Waddell relates the story, “The Adventures of Nera” (Echtra Nerai). It takes place as Medb and Ailill were celebrating Samhain. Nera left the feast to temporarily free a captive. He had been bound the day before and was complaining of thirst. Nera gave the captive a drink and then rebound him. When Nera returned to the feast, he found that beings from the Otherworld had left their sid. A sid is a fairy mound where beings from the Otherworld live. They had burned the hall of the feast. In its place, they left a pile of heads. Nera followed the Otherworldly beings into Oweynagat. He found an Otherworld wife there. He made his home there. Over time, his Otherworld wife told him that what he saw at Samhain was a vision of a possible future. Cruachan would be destroyed next Samhain unless Nera would warn people. After he warned Medb and Ailill, they destroyed the sid. Nera, however, had already returned to his home in the sid. He remains trapped in the Otherworld with no way to return to this world.

Many of these folktales have monsters of one type or another emerging from Oweynagat. Some specifically occur on Samhain. In these tales, monsters walk the earth. Waddell suggests that these folktales may have been the origin of Halloween customs.

O’Brien may disappoint cat-loving witches in “The Mórrígan’s Cave – Oweynagat, at Rathcroghan/Cruachan, County Roscommon, Ireland”. O’Brien said that no relationship exists between the Mórrígan and cats -house or wild. Felines are largely absent from Irish folklore.

According to O’Brien, the Mórrígan transforms herself into a crow, raven, she-wolf, heifer, eel, an old hag, and a beautiful young woman. Her colors are red, white, black, and grey.

In their video, “The Mórrígan & the Irish Otherworld – Not the Underworld!,” O’Brien rejects the idea that the ancient Irish had an Underworld. The Otherworld had no direct association with death. Instead, they had an Otherworld. The dead go to specific places in the Otherworld. They described the Irish Otherworld as parallel to this world, like a parallel universe. Both Medb and the Mórrígan represent sovereignty. Medb’s sovereignty is of this world. That of the Mórrígan is of the Otherworld.

O’Brien described the cave as having an architectural structure at its entrance. Waddell reported that the entrance to the cave consists of masonry, roofed with slabs. The lintel piece above the entrance has an inscription “written” in ogham script. That inscription translates to “Fraich, son of Medb.” Another stone has an untranslatable ogham inscription.

According to O’Brien, the cave is very, narrow, but then widens out into a natural cave. The cave has a length of about 9 m (30 feet) underground. O’Brien reported that some older locals remembered a second chamber. That second chamber has since collapsed. Waddell reported that in 1864, Samuel Ferguson estimated the length of the tunnel to be about 36 m (118 feet) long.

Daithi’s Stone

Drawing of Daithi’s Tomb 1903. [Credit: William Frederick Wakeman, Public domain]

Tradition holds that Daithi, the last Pagan King of Ireland is buried here.  Daithi probably died in the Fifth Century C.E. Radiocarbon dating of charcoal fragments fails to support that claim. Radiocarbon testing returned a date of the 1st or 2nd Century B.C.E.

This site consists of a small enclosure with a diameter of 38 m (about 125 ft). In its center, lies a tumulus, an artificial mound. Emerging from that tumulus, stands a red sandstone pillar. That pillar stone stands 1.8 m high (roughly 6 ft.). In 1844, O’Donovan, a surveyor, reported about a disturbance at that site. Since his last visit in 1837, cattle had knocked down the pillar stone. In 1852 another visitor, R. R. Brash, reported that the pillar stone had been placed upright. This indicates continued maintenance millennia after the abandonment of Cruachan. Given the time period, people probably righted that felled pillar during the catastrophic Potato Famine (1845-1852).

Unexpected connection

In 1779, Gabriel Beranger visited Rathcroghan. He reported on the condition of the site at that time and made drawings of it. His report was not published till a century later in 1871 by Dr. William Wilde, Oscar’s father.