The earthworks that once defined it have been levelled to the point where only aerial photography and a careful eye for vegetation reveal its presence, yet what that presence hints at is considerable. Aerial photographs taken by the Geological Survey of Ireland in 1974 show the outline clearly enough, and measurements taken from the variations in plant growth suggest this was once a bivallate rath, meaning a ringfort enclosed not by one defensive circuit but by two concentric banks and at least one substantial ditch between them.

A rath is an earthen ringfort, a form of enclosed farmstead common across Ireland from the early medieval period onwards, typically associated with a single farming family and their livestock. Most consist of a single bank and fosse, the fosse being the external ditch from which the bank material was dug, so a bivallate example with two banks and a wide outer ditch represents something rather more substantial. At Knockburrane, the inner bank survives in traceable form from the north-west, around through north and east to south-east, and is between 3.5 and 5 metres wide. The fosse enclosing it ranges from 7 to 12 metres in width, and beyond that an outer bank, roughly 4 metres wide, can be followed for most of the circuit, fading out only to the south and west. The whole enclosure measures approximately 40 metres north to south and just over 41 metres east to west. A field ditch running east to west cuts across the northern sector, a later intrusion that further complicates any reading of the original ground surface. The site appears on Ordnance Survey maps from the 1841 to 1842 survey and again on the 1914 to 1915 edition, suggesting it was at least partially legible as a feature well into the twentieth century, before agricultural work reduced it to what it is now.