The trees are the giveaway; plantings like this rarely happen by accident, and in the Irish countryside a ring of old growth on slightly raised ground almost always signals something underneath or behind it.

The site at Drumaliss is most likely a rath, the term for a circular earthen enclosure, typically of early medieval date, that would once have enclosed a farmstead or the home of a local lord. The defining bank survives, measuring roughly 30.5 metres across from east to west and 30 metres north to south, with an earthen bank whose base is about 2.1 metres wide. On the northern, southern, and western sides, this bank retains an outer stone facing, though elsewhere it has been reduced to a stone-faced scarp. There is no visible fosse, the term for a surrounding ditch, and no clear entrance can be made out. By the time the Ordnance Survey produced its six-inch map in 1834, the enclosure was already being labelled simply as a "fort" in gothic lettering, which was the standard convention cartographers of that period used to flag sites of apparent antiquity. What the map also shows is the ring of trees already present, suggesting the rath had by then been repurposed as a tree-ring, a common enough practice in Ireland where old enclosures were tidied up and planted, sometimes to shelter livestock, sometimes simply because the boundary was a convenient one to keep.