That sequence alone is quietly arresting: whoever constructed this souterrain, an early medieval underground structure typically used for storage, refuge, or both, did so before anyone had raised walls at ground level. The dwelling came later, arranged around what was already buried beneath it.

Excavations carried out in 1999 revealed the full layout of the complex. Entry from the hut site was through a square opening just half a metre across, sealed by a stone slab, dropping into an earthen entrance passage roughly one and a half metres wide and roofed with stone lintels. From there, a series of creepways, low connecting passages that required a person to crouch or crawl, led through two drystone-built passages arranged in different orientations. Passage 1 ran east to west and stood nearly two metres high, its walls built from dry-laid stone that inclined inwards to meet a roof of large flat slabs. Passage 2 ran north to south, similarly constructed, and included an air-vent at its northern end, a detail that suggests careful attention to ventilation rather than purely defensive or storage concerns. Beyond the passages, two earth-cut chambers sat at the far end of the system, connected by their own creepway. The westernmost of these contained a circular pit roughly a metre across and a metre deep, filled with stones and redeposited subsoil, which the excavator interpreted as a sump for draining water. A construction shaft discovered immediately to the north of the chambers, measuring over two and a half metres deep, records how the builders originally dug down to create the space. Lines of slots and stake-holes extending southward from the souterrain may reflect the timber frameworks used during that process.