Archaeologists have uncovered a mysterious monument in the heart of the Carrowmore megalithic complex in Co Sligo.

A team of archaeologists from IT Sligo, directed by Dr. Marion Dowd and James Bonsall, made the discovery during a two-week excavation.

Carrowmore is the oldest and largest collection of megalithic tombs in Ireland, with passage tombs dating from 3,600 BC.

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According to, the site of the excavation was first thought to be a barrow, which are circular earthen monuments surrounded by a circular ditch. Typically dating back to the Bronze Age and Iron Age, the sites range from between 4,000 and 1,500 years old.

“Our excavations have revealed that this monument does not appear to be a barrow at all. So far, we cannot find any parallel for it in Ireland,” Dr. Marion Dowd said.

The Leitrim Observer reports that the archeologists “found that the circular ditch surrounded a central raised area that consisted of a thick circular layer of stone. Inside this was a sunken area with black, charcoal-rich soils.”

Prehistoric tools made from a hard stone known as chert were found within and around the monument.

“We have a lovely collection of chert scrapers and blades from the monument. These would have been used for activities such as working animal hides, cutting and preparing food, basket working and bone working,” Dr. Dowd said, “essentially a prehistoric tool kit.”

“We are now focussed on post-excavation analyses of all the materials recovered during the excavation and hope to have scientific dating in the next few months. At the moment what we can say is that we have quite an enigmatic prehistoric monument: something different and new.”

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