The structure consists of a subcircular mound of small angular stones, measuring approximately 9.9 metres across and standing 0.75 metres high. What makes this cairn particularly intriguing is the rectangular pit that has been excavated into its centre, with the displaced stones piled up towards the northeast, creating an unusual, lopsided profile that sets it apart from typical prehistoric monuments in the area.

The cairn's altered appearance has led to speculation about its purpose and history. While it bears the characteristics of ancient burial cairns found throughout Ireland, the deliberate modification suggests it may have served a more recent, practical function. One compelling theory is that it was repurposed as a trigonometrical station; a survey point used for mapping Ireland's landscape in the 19th and early 20th centuries. These stations often utilised existing high points and structures, and surveyors frequently adapted ancient monuments for their purposes.

Located near Culoort, this enigmatic structure represents the layers of history that characterise Ireland's archaeological landscape. Whether it began as a Bronze Age burial site later adapted for modern surveying, or was purpose-built for cartographic work, the cairn stands as a reminder that Ireland's ancient monuments often have complex histories that span millennia. Its remote location on Sheemore's boggy summit has likely protected it from further interference, preserving this archaeological puzzle for future generations to contemplate.