This modest enclosure, measuring roughly 26 metres from northeast to southwest and just under 12 metres across, consists of a low boundary wall built from earth and stone that has weathered centuries of Irish seasons. The site's most intriguing feature sits at its northern corner; a circular stone foundation approximately 3.4 metres wide, constructed from a single course of substantial stones that hint at a structure long since vanished.

The interior of the enclosure tells a fragmented story through scattered stones and rough, rocky outcrops that break through the ground surface. While the site's original purpose remains uncertain, its proximity to the Black River and the care taken in constructing the stone foundation suggest it held significance for the local community. The name 'Caldragh' itself, preserved through successive map editions, likely derives from Irish place-name elements that could provide clues to its historical function.

This site forms part of Donegal's rich archaeological landscape, documented comprehensively in the 1983 Archaeological Survey of County Donegal. The survey, compiled by Brian Lacey and his team of researchers, catalogued field antiquities spanning from the Mesolithic period through to the 17th century, ensuring that even modest sites like Caldragh remain part of the county's recorded heritage. Though it may lack the grandeur of larger monuments, this small riverside enclosure represents the type of everyday archaeological site that helps piece together patterns of settlement and land use in rural Ireland across the centuries.