The investigation of a monument in the heart of the Carrowmore passage tomb complex, one of Ireland's four main passage tomb centres, was the first excavation to take place here in over twenty years. The site had been classified as a barrow of unknown date. Excavations in 2019 revealed a circular monument comprising a central depression surrounded by a band of multiple layers of stones and gravel that in turn was enclosed by a wide but shallow ditch. An assemblage of 35 lithics, predominantly chert, was recovered, representing a series of events in the Neolithic and possibly into the Bronze Age. Complementing the lithic assemblage, optically stimulated luminescence returned a Neolithic date for the monument. The site is central to and contemporaneous with the megalithic tombs at Carrowmore and likely fulfilled a ceremonial function. [ABSTRACT FROM AUTHOR]