One of them carries the designation Petrie No. 2, a reference to the nineteenth-century antiquarian George Petrie, whose numbering system was among the earliest attempts to catalogue the site systematically before much of it was lost to quarrying and land clearance.

Passage tombs are a specific form of prehistoric monument in which a stone-lined corridor leads into a central burial chamber, the whole structure typically covered by a cairn or earthen mound. At Carrowmore, the examples tend to be smaller and structurally simpler than the great passage tombs of the Boyne Valley, but they are, in many cases, considerably older. The site as a whole has produced radiocarbon dates pushing back into the fifth millennium BC, making some of these monuments among the earliest megalithic constructions anywhere in Europe. Seán Ó Nualláin's detailed survey, published in 1989 as the fifth volume of the Survey of the Megalithic Tombs of Ireland, remains the foundational scholarly record for the county, bringing together measurement, structural description, and comparative analysis for monuments including this one. Ó Nualláin's work was essential in establishing just how many tombs had survived, and how many had not, across the Carrowmore complex.