The circular earthwork that once stood here, recorded on the first edition of the Ordnance Survey map, has left no visible trace above ground. What remains, opening quietly on the north side of the rise, is the entrance to a souterrain: a narrow, lintelled mouth measuring just 1.3 metres wide and 0.3 metres across, leading down into the earth.

Souterrains are underground stone-built passages associated with early medieval ringforts, the circular enclosed settlements that were the basic unit of rural life in Ireland roughly between the fifth and twelfth centuries. They were likely used for storage, refuge, or both. The one at Ballard is a notably well-made example. Its drystone passage, 2.3 metres long, slopes sharply downward to a maximum depth of 1.2 metres, the walls constructed in regular courses of flat slabs, with larger stones placed deliberately in the lower sections for stability. The sides corbel slightly inward, meaning the walls lean gently toward each other as they rise, a technique that lends structural strength without mortar. The passage, averaging about a metre in width, is roofed with flat slabs laid across the top. At its far end, a small lintelled creep way, only 0.3 metres high, appears to connect into a second passage beyond, though the full extent of what lies further in is not recorded.

The rath itself, the banked enclosure that would have defined the settlement above ground, is entirely gone, absorbed into centuries of agricultural use and the slow work of the boggy ground around it. What survives is the hidden infrastructure, the part built to endure below the surface, now outlasting the walls and earthworks it once served.