The only evidence of its existence comes from the 3rd edition of the Ordnance Survey 6-inch map, where cartographers marked it as an arc of hachures; those distinctive parallel lines used to indicate earthworks or slopes. These markings suggest the structure originally curved from the east-northeast round to the south-southeast, forming what would have been a substantial portion of a circular or semi-circular enclosure.

The site occupied prime agricultural land, situated on fairly good pasture that would have made it an attractive location for early settlement or defensive purposes. Drumlins, those characteristic egg-shaped hills formed by glacial activity, are common features across Donegal's landscape and often provided ideal spots for ancient communities; their elevated positions offered both defensive advantages and good drainage for crops and livestock.

Today, no physical trace remains of this enclosure at Summerhill. Modern farming practices, natural erosion, and the passage of time have completely erased what was once likely an important local landmark. The site's documentation in the Archaeological Survey of County Donegal, compiled by Brian Lacey and his team in 1983, ensures that at least the memory of this lost monument survives, even if the earthworks themselves have returned to the soil.