Sitting on the flat edge of a gentle east-west ridge in County Tipperary, with the ground sloping away to the north-west towards a stream and another hill rising on the far bank, this is a monument that has held its shape against the landscape for well over a thousand years, and still commands its ground.

The fort is what archaeologists call bivallate, meaning it was defended not by a single enclosing bank and ditch but by a doubled system. A ringfort, or rath, was typically the enclosed farmstead of an early medieval Irish family, the earthworks marking both a practical boundary and a statement of status. At Lissava, the inner earthen bank encloses a roughly circular interior some 50 metres across from north to south, and the overall diameter of the whole structure reaches nearly 73 metres east to west. Between the inner and outer banks runs a fosse, a flat-bottomed, steep-sided ditch roughly 2.8 metres wide and 1.6 metres deep, and the outer bank itself is particularly substantial, with a flat top nearly five metres wide at its crest and standing over two metres high on its outer face. That outer bank is, unusually, generally higher than the inner one, especially in the southern quadrant. Some damage has occurred over the years: the fosse has been filled in across portions of the circuit, and the outer bank in the north-north-west has been quarried into. A narrow gap of about 1.5 metres in the eastern quadrant appears to serve as a cattle break. Yet the overall form remains clear, and corresponds closely to how the site appeared on the Ordnance Survey six-inch map of 1906, suggesting the earthworks have changed relatively little in the intervening century.