The earthwork beside the Morning Star river in Crean, County Limerick, breaks that expectation quietly. It is rectangular, a platform of ground measuring roughly 36.5 metres north to south and 45.7 metres east to west, sitting on low, poor land at the edge of a marsh. The bank that once ran along its perimeter has vanished entirely on the northern side, and wherever the original entrance once stood, the ground no longer offers any clue.

The site was described by O'Kelly in 1942 to 1943, and the account has a provisional, investigative quality that makes it rather interesting to read. O'Kelly noted an elongated hollow in the south-western quadrant of the platform, which he suggested might be a collapsed souterrain. A souterrain is an underground passage or chamber, typically stone-lined, associated with early medieval settlement and used variously for storage, refuge, or ventilation. Their roof structures could fail over time, leaving exactly the kind of depression O'Kelly observed here. Whether that hollow does conceal a souterrain remains, as far as the record shows, unconfirmed. An aerial photograph taken in September 2002 for the Archaeological Survey of Ireland provides additional documentation of the site as it appeared from above, though the ground-level interpretation remains much as O'Kelly left it.

The site sits in a landscape shaped by its proximity to marsh and river, which means the ground underfoot can be soft and the visibility of earthworks is often better from a distance or from above than at close quarters. The rectangular outline is the principal thing to look for, along with the surviving bank on the southern and eastern sides. The hollow in the south-western corner, if it can be located, gives a sense of what might lie beneath the surface. Access to sites like this typically requires crossing private farmland, so seeking local permission beforehand is both courteous and practical. Autumn and winter, when vegetation dies back, tend to reward the careful observer more than the summer months.