Though no visible traces remain on the surface today, archaeological surveys have documented this subterranean complex amongst the rocky outcrops that characterise the local landscape.

The souterrain consists of two chambers connected by a narrow passage, demonstrating the typical construction methods used throughout Ireland during the early medieval period. The first chamber measures approximately 10 feet in length, 4 feet wide, and 4 feet high; just large enough for a person to crouch or sit comfortably. A cramped passage, merely 6 feet long and 18 inches wide, leads to the second, more spacious chamber extending 14 feet in length. Intriguingly, investigators noted possible evidence of additional cavities beyond the known chambers, suggesting the structure may be more extensive than currently documented.

These underground passages, found throughout Ireland but particularly common in Ulster, were typically built between the 6th and 12th centuries AD. They were constructed by digging into the earth and lining the walls with stone, creating dry, secure spaces that maintained relatively constant temperatures year round. The Killinangel More souterrain, recorded by the National Monuments Inventory and later included in the Archaeological Survey of County Donegal (1983), represents one of hundreds of such structures that honeycomb the Irish countryside, silent witnesses to a time when communities needed hidden refuges close at hand.