At Ardla in County Dublin, a substantial early medieval ringfort once occupied a prominent rise overlooking the coast, its two concentric earthen banks visible enough in 1837 to be carefully recorded by the Ordnance Survey as a bivallate enclosure, meaning a ringfort defined by two banks and ditches rather than the more common single circuit. At its widest point it measured approximately 110 metres across, which would have made it a considerable presence in the landscape. Today there is nothing to see. The site was levelled during the 1970s and converted into a town dump.

Ringforts are among the most common archaeological monument types in Ireland, with tens of thousands once scattered across the country. They served as enclosed farmsteads during the early medieval period, roughly between the fifth and twelfth centuries, and their earthworks could range from modest single-banked enclosures to more elaborate multivallate constructions like the one at Ardla. A bivallate example on an elevated coastal site would have been a reasonably significant settlement, its position affording both visibility and a degree of natural defence. The 1837 Ordnance Survey six-inch map records it plainly, marked simply as "Fort", part of the first systematic mapping of Ireland and a document that now preserves evidence of hundreds of sites that no longer exist in any physical form. The record in Healy (1975) confirms what the landscape can no longer show.

Because the earthworks were removed entirely during the 1970s redevelopment, the site is not visible at ground level, and there is no monument to locate or examine in the field. Its interest now lies almost entirely in the archival record, particularly that early Ordnance Survey mapping, which researchers and those with access to historical map archives can consult to understand what was once there and where it stood relative to the coastline. The compilation of this record by archaeologist Geraldine Stout reflects the broader work of documenting losses as much as survivals, a task that becomes more pressing the further such destructions recede from living memory.