This standing stone, measuring 0.65 metres high, 0.77 metres wide, and 0.47 metres thick, was oriented east to west and bore an impressive collection of 33 cup marks; shallow, circular depressions carved into the stone's surface by people thousands of years ago. Fourteen of these mysterious markings decorated the south face, with a single cup mark on the western side and eighteen scattered across the top surface.

The stone was documented during the comprehensive Archaeological Survey of County Donegal conducted between 1980 and 1981, when photographer Paul Walsh captured what would become one of the last known images of this ancient monument. The survey, led by Brian Lacey and his team of archaeologists, catalogued the county's field antiquities from the Mesolithic period through to the 17th century, preserving vital information about monuments that might otherwise be lost to time.

Unfortunately, this proved prescient for the Doon Glebe standing stone. In June 2013, the monument was reported missing from its location on the low-lying marshy ground where it had stood for millennia. Whether removed, buried, or destroyed, its disappearance represents a significant loss to Ireland's archaeological heritage. The cup marks it bore remain a mystery; these enigmatic symbols, found throughout Ireland and Britain, continue to puzzle archaeologists who debate whether they held ritual, astronomical, or territorial significance for the prehistoric communities who created them.