They are not natural formations but deliberately excavated shelters, which places them in a category of site that tends to attract quiet archaeological curiosity rather than fanfare.

What draws particular attention is what was found inside one of them: a large quantity of broken flint. When a researcher named Martin investigated the site in the early 1930s, he noted a strong resemblance between these flints and those typically recovered from raised beaches elsewhere in Ireland. Raised beaches are ancient shorelines left stranded above the current tide line as land levels shifted after the last ice age, and the tool debris associated with them tends to indicate prehistoric human activity, sometimes very early prehistoric activity. The comparison Martin drew was suggestive rather than conclusive, but it pointed towards the possibility that these caves sheltered people working flint at a time when the coastline itself looked quite different. More recently, additional traces of flint have been recorded at the site, which at least confirms that the material is not a one-off find scattered by later disturbance.

The site sits at a place still sometimes called Dunbur Head, a stretch of the Wicklow coast that sees walkers but relatively few people looking deliberately for archaeology. The caves are cut into the wall of the trench rather than opening directly onto open ground, which means they can be easy to overlook if you do not know to look along the southern face of that earthwork channel.