Its existence rests on a single aerial photograph taken in 1963, in which a rounded form resolves itself from the landscape in a way that suggests the buried outline of a much older feature. Whether it is genuinely there, and what it once was, remains unconfirmed.

Circular enclosures of this kind, when they do exist, are usually the ghostly remnants of early medieval settlements or enclosed farmsteads, their ditches and banks long since levelled by centuries of ploughing and soil movement. They survive not as physical features but as cropmarks or soilmarks, visible from the air when differential moisture or growth betrays the presence of disturbed ground beneath. The 1963 photograph caught something at Sruhaun that looked like one of these, though no subsequent ground investigation appears to have confirmed what lies below the surface.