Home Substantial portion Cork Harbor rock structure declared Stone Age tomb

Cork Harbor rock structure declared Stone Age tomb


Ever since the discovery of a stone dolmen on the eastern shore of Cork Harbor in southern Ireland many years ago, archaeological opinion has been divided on the exact nature of the Carraig stone at Mhaistin. New research now seems to prove that it is a Stone Age tomb, as many experts have always believed.

According to the Irish Examiner , Connemara-based archaeologist Michael Gibbons says his research has uncovered conclusive evidence regarding the age and purpose of the monument. He argues that it is now possible to confidently identify the Carraig á Mhaistin Stone in Rostellan, also known as the Rostellan Dolmen, as a megalithic tomb. It had sometimes been suggested that it was an 18th century folly, a purely ornamental garden building serving no purpose.

A close up of the Rostellan Dolmen, Carraig á Mhaistin, which was recently identified as a Neolithic intertidal tomb. (Howard Goldbaum / DC BY NC 4.0 )

Carraig to Mhaistin Origin: A Long-standing Debate

Historian and author Kieran McCarthy addressed the debate over the provenance of the Rostellan Dolmen in his book The Little Book of Cork Harbor . An excerpt from the book published in the Cork Independent in 2019 explained that the dolmen standing at Rostellan, at the eastern end of Cork Harbour, are akin to portal tombs, but it is difficult to identify it categorically as such.

A portal tomb is a single-chamber megalithic tomb. It marks a burial site in a very distinctive way, with two or more vertical megaliths supporting a large horizontal flat capstone or ‘table’ at an angle.

The Cork Harbor monument is made up of three standing stones topped by a capstone, which once fell but was later re-erected. At high tide, the site is submerged and it is difficult to access it through the mudflats. An easier route is through the adjacent Rostellan wood. The wood was planted as part of the former Rostellan House estate, built in 1721 by William O’Brien (1694-1777), the fourth Earl of Inchiquin.

The Carraig Stone at Mhaistin has sometimes been identified as a folly because the estate has a castle tower-like folly nearby, named Siddons Tower after Welsh-born actress Sarah Siddons. According to the Heritage Daily, the folly was built by Murrough O’Brien, the first Marquess of Thomond, in the late 18th century. This led to the suggestion that the Carraig á Mhaistin Stone was another of the Marquis’s follies.

The now ruined Siddons Tower folly is located near the Carraig á Mhaistin dolmen, contributing to the misidentification of the cairn.  (Public domain)

The now ruined Siddons Tower folly is located near the Carraig á Mhaistin dolmen, contributing to the misidentification of the cairn. ( Public domain )

This uncertainty about the age of the monument has meant that it has missed its rightful place in the survey of the megalithic tombs of Ireland carried out by Professor Ruaidhrí de Valera and Seán Ó Nualláin more than 40 years ago. According to the Irish Examiner, Gibbons said: “At this time it was suggested that he might have [been] a folly or type of ornamental structure commissioned by local nobility in the neighboring estate of Rostellan Castle and dating from the 19th century.

New evidence for the megalithic tomb theory

Gibbons said his recent visit to the site led to the discovery that the small chamber of the tomb sits at the western end of a cairn, which is 25 meters (82 feet) long and 4.5 meters ( 14.7 feet) wide. This is quite conclusive, as portal and court tombs “sometimes have long, intact cairns which are both intended to provide structural support for the chamber itself and to enhance the visual presence in the landscape”, a said the Irish Examiner.

He added that the cairn is partially submerged in “estuarine mud”, and that a significant portion will likely be uncovered below the surface. Although it is not known when sea level rise submerged the area, it is believed that sea levels in this part of the harbor have remained stable for the past 2,000 years.

Despite its disputed provenance, some guidebooks have listed Carraig á Mhaistin Dolmen as the only intertidal portal tomb in Ireland. While Gibbons agrees with them that the dolmen is indeed an intertidal megalithic tomb, he argues that there are in fact two such tombs in Ireland. The only other known intertidal portal tomb is at ‘the Lag’ on the River Ilen, between Skibbereen and Baltimore in West Cork.

Interestingly, the portal tombs are often known locally as “The Bed of Diarmuid and Gráinne”, in reference to the Irish folk tale “The Pursuit of Diarmuid and Gráinne”. The story tells of a love triangle between the great warrior Fionn mac Cumhaill, the beautiful princess Gráinne and her lover Diarmuid Ua Duibhne.

Gibbons’ research should give the Rostellan Dolmen its rightful place among the megalithic tombs of Ireland. As a Neolithic tomb, it has far greater archaeological value than an 18th century folly – an architectural extravaganza with no particular utility.

Top image: New research has identified Carraig at Mhaistin, the Rostellan Dolmen, more definitely as a Stone Age megalithic tomb. Source: Howard Goldbaum / DC BY NC 4.0

By Sahir Pandey