It is a burnt mound, a type of prehistoric site found throughout Ireland and Britain, and one of the more enigmatic categories of monument to survive from the Bronze Age. The term refers to a distinctive accumulation of stone that has been repeatedly heated and then plunged into water, the thermal shock eventually shattering each stone beyond reuse. Over time, these discarded fragments build up into a mound, typically crescent-shaped or kidney-shaped, almost always found near a water source or in a low-lying, damp location.

Archaeological testing carried out under licence number 08E0352, with findings reported by Duffy in 2008 and 2011, established the dimensions of the deposit at roughly twelve metres along a northwest to southeast axis and approximately four and a half metres across, with a surviving depth of around twenty centimetres. That is a moderately substantial accumulation, suggesting repeated and sustained use of the site over time. What exactly burnt mounds were used for remains a matter of some debate among archaeologists; cooking, bathing, hide-processing, and textile preparation have all been proposed, and it is quite possible that different sites served different purposes. What is clear is that the activity was labour-intensive, organised, and recurrent. The Cornecassa example is preserved in situ, meaning it has not been removed or reconstructed but remains where it was originally deposited, undisturbed beneath the slope.