This rugged landscape, stretching roughly 700 metres north to south and varying between 50 and 220 metres east to west, represents the island's highest ground and contains evidence of human occupation spanning centuries. The area's natural defences are immediately apparent; a narrow 40-metre-wide isthmus forms a natural ditch leading to the southern section, where the grass-covered remains of a stone wall, approximately 40 metres long and 2 metres wide, still stand. Historical records from the Civil Survey of 1654-56 mention a 'Little Castle' here, and whilst John O'Donovan described it in 1835 as a modern square castle of lime and stone, no visible traces of this structure remain today.

The peninsula's archaeological complexity becomes evident as you move eastward. About 80 metres from the entrance, a substantial earthen and stone bank runs for 105 metres alongside a defensive ditch, whilst further north, the landscape is dotted with various enclosures and structures. These include square enclosures built against linear banks, mysterious lines of water-rolled beach stones forming geometric patterns, and what appear to be four small stone-built hut sites with rectangular plans. The most impressive defensive feature, however, is found where the peninsula narrows again to form another 50-metre-wide isthmus. Here, four massive earthen banks with three intervening ditches dominate the landscape, known locally as 'Balor's Fort' after the legendary one-eyed giant of Irish mythology. A narrow causeway cuts through these formidable defences, which once protected the inner settlement area.

Beyond these defences, the peninsula opens up to reveal at least twenty surviving 'hut circles' scattered across a south-facing slope. These circular or oval structures, typically about 10 metres across with substantial earthen and stone banks up to 3 metres wide, were built directly on the island's rocky surface before the development of turf cover. Among these ancient dwellings, three sites bear the romantic name 'Diarmuid and Grania's beds', though their actual archaeological significance remains unclear. Near one of the huts, a rock-cut well provided fresh water to the inhabitants. The easternmost section of the peninsula, accessed only by crossing another rock-cut ditch, contains a collapsed stone enclosure perched precariously on the cliff edge. Local tradition offers no explanation for these structures' original purpose, but their positioning on this remote Atlantic outpost, seven miles from the Donegal mainland, suggests they served communities who valued the island's natural defences and commanding views of the surrounding seas.