What makes the site quietly puzzling is what no longer exists within it. A second, smaller circular feature, roughly twenty metres across, was recorded inside the southern half of the larger enclosure on the first Ordnance Survey six-inch map of 1838, appearing to abut or perhaps share the bank along its south-eastern to southern edge. Today, there is no surface trace of it whatsoever.

Enclosures of this kind, roughly circular or subcircular earthworks defined by banks and sometimes ditches, are among the most common surviving monuments in the Irish countryside, often associated with early medieval settlement and farming. The larger enclosure at Wherrew measures around sixty metres in diameter, a size consistent with a substantial ringfort, the type of enclosed farmstead that housed farming families and their livestock across Ireland roughly between the fifth and twelfth centuries. The presence of a smaller enclosure set within it is the more unusual detail. Such nested arrangements do occur, sometimes interpreted as evidence of a subdivided interior, a separate animal pen, or a later addition to an already established site. Whether the inner feature at Wherrew ever had a physical bank of its own, or was perhaps defined only by a shallow ditch or fence line that left little lasting impression, is now impossible to say from the surface alone. The 1838 cartographers recorded what they saw, or inferred, and the ground has since moved on.