What survives is a subcircular rath, a type of enclosed farmstead common across early medieval Ireland, typically defined by one or more earthen banks and ditches and used as a defended homestead. This one measures roughly 32 metres north to south and 28 metres east to west, dimensions that suggest a reasonably substantial enclosure in its day. The trouble is that very little of it remains as built.

The site has been quarried extensively, both around its perimeter and through its interior. A degraded earthen bank can still be traced from the eastern side, curving south and continuing round to the northwest, but beyond that arc the enclosing element is a scarp, the kind of abrupt edge left when material has been cut away rather than heaped up. The quarrying appears to have targeted the hillock itself, using the raised ground of the rath as a convenient source of stone or gravel over an unknown period of time. This is not unusual in Ireland; ringforts across the country have been broken up for road fill, field clearance, and building material, particularly during the eighteenth and nineteenth centuries when agricultural improvement put pressure on every lump and ridge in the landscape. What makes Bunavan worth noting is precisely the degree to which that process has advanced, leaving a site that reads more as an absence than a presence, the outline of something rather than the thing itself.