Part of its outer bank has been absorbed into a field fence, its original entrance has been lost entirely, and the U-shaped fosse, or defensive ditch, that once ringed it is almost completely silted up along the north and east sides. What is left is the kind of monument that rewards attention precisely because it has been half-forgotten; the site has not been preserved so much as endured.

The structure is a rath, the Irish term for a ringfort, a form of enclosed farmstead built throughout Ireland roughly between the early medieval period and the Viking Age, though many were in use well before and after those broad brackets. Ringforts typically consisted of a raised circular bank with an outer ditch, enclosing a domestic area where a farming family would have kept animals and sheltered from the hazards of a competitive rural world. The Lackan example, as described in 1971, showed a bank best preserved along its south and south-western arc, with traces of earlier cultivation ridges still faintly visible inside the enclosure, running roughly north-northeast to south-southwest. Those ridges suggest that at some point, long after the fort ceased to function defensively, the enclosed ground was put back to agricultural use, layering one era of farming over another.

The views from the site towards the north, east, and northwest are good, which may explain why the location was chosen in the first place; control of sightlines mattered to anyone deciding where to build a secure homestead. The bank's exterior has been modified and incorporated into field boundaries over time, and several gaps disturb its circuit, so the impression today is of a place that has been quietly cannibalised by the working landscape rather than dramatically ruined.